Home: Updates

August 29, 2011

• Posted a link to a Belorussian translation of the Coat Color Mutations page.

April 13, 2011

• Updated my About page with a new Publications section.

• Added a reference providing evidence that the Black Death was caused by Yersinia pestis to the Wild rats and disease page.

January 21, 2010

• Added an update to the Dumbo rat mutation and human analogues.

June 11, 2009

• Added a link to a three-dimensional view of the human eye to the rat's eye page.

• Added more information to the allogrooming section of the glossary.

• Added more references and information to the History of the Norway Rat page.

• Added more data to the Spaying and tumor incidence in a pet rat population article

October 2, 2007

• Added a new article: Spaying and tumor incidence in a pet rat population

July 23, 2007

• Added a new article: comparative studies of different types of rat bedding

• Added new information from a rat rescue organization on fertility after castration to the neutering page.

• Added new content and references to the Wild Rat Bites page.

• Added a new article: Do rats have a collapsible skeleton?

• Added a few new references to the Wild rats and disease page.
• Added a new article: 'Thoughts on human and rat ethology," linked from the What is my rat doing? FAQ

• I am very sad to say that Tucker died today. He has had a very benign old age, strolling about and eating treats right up to the end (he ate a number of grapes just yesterday). He had no paralysis, no tumors, no respiratory issues, no lingering or suffering. He simply got slower and slower, and his breathing got heavier, as he moved about the cage. But he was still able to climb into his beloved hammock up to the day before he died. In the end, I think he was just resting with his head looking out of the nestbox, like he often does, gazing at the world and perhaps wondering when the next treat might be coming his way... and he slipped away. I found him so this afternoon.

• Added a new article How do albino rats differ from pigmented rats?

• New content and references added to the What do rats see? page.

• Added a section to the About page on how to cite online articles on this website.
• Added new references to the Wild Rats and Disease page.
• Added new references to the Where do rat coat colors come from? page.

• I am very sorry to report that Bobbin died today. He had a progressive neurological condition that finally took his life. He was a gorgeous, handsome rat and his grey blazed face will be greatly missed in our lives. He was 2 years and 5 months old.

• Added a cage & toddler photograph to the Bobbin, Tucker, and Grommet page.

• I am very sad to sat that Grommet died today. He had a tumor, and during the surgery this morning the vet found that the tumor was just too deep and invasive for him to save Grommet. Grommet was a fine little guy, the sometimes-alpha of our latest colony of three. He and Bobbin vied for the top, but they were rather laid back about it and never fought seriously. Grommet will be greatly missed. He was 2 years and 4 months old.
• Added a new page for Bobbin, Tucker, and Grommet.

• Added a drawing of the phylogeny of Rattus species to the History of the Norway rat page.

• Added new information and references about the speciation of the Rattus genus to the History of the Norway rat rat page. 

• Added a new section to the Pet Rat FAQ

• Added more references and discussion of spontaneous tumors to the pregnancy and mammary tumors article.

• Added a new article: Pregnancy and mammary tumors on the protective effect of pregnancy on the incidence of chemically-induced tumors later in life.

• Added new references and a box on domestic rats to the rat bite fever section of the wild rats and disease page.

• Added a new bruxing sound to the Norway Rat Vocalization page. Bruxing was produced by a rat named Celia. I have shared the sound file here with the kind permission of Angelrats of Rat Tales.

• Added a link to the New York Times article Nice rats, nasty rats, maybe it's all in the genes.
• Added a table of informal dumbo vs. standard rat head measurements to the Dumbo rat mutation and human analogues page.

• Added a link from the main page to a Russian translation of portions of my site.

• Added new references to the Do rats have a dry bite? page.

• Added a new box and reference on substances that glow under a black light to the rats under a black light page.

• Added a photograph of Spritely, an Australian blue rat, and more references to the Australian blue rats: a hypothesis page.

• Added a paragraph to the aggression page describing the design of escape chambers used during introductions of intruders into resident colonies to decrease levels of injury and death.

• Added a new section to the aggression page on intruder-directed aggression in residents living in a burrow-digging cage vs. a laboratory cage.

• It is with great sadness that I must report that Snip died on May 18, 2005. He was nearly 2 years and 10 months old. He had been in a gentle decline for the past six weeks or so: his hind legs were very weak and he slept a lot. He breathed hard and his body temperature was a little cool, but he still retained his sweetness and enthusiasm for life and food up until his last day. We knew he probably didn't have much time left, so his death was not a shock, but we are still devastated and miss him very much. Of the three brothers Widget, Cricket, and Snip, Snip was by far the calmest and squishiest of them all. For the past year Snip has been happy to sit and brux and snooze in my arms, or on my lap, or next to me on the couch. He was content to sit there and be petted for an hour or more at a time. This made him extra-special and dear, so losing him is wrenching. But Snip had a wonderful long life, full of food and exploration and fun and burxes, and that is truly cause for celebration.

• Added a new image of an LSE mouse to the dumbo rat page.
• Added a new section to the aggression page on introduced rats developing stress-induced ulcers within hours of being introduced/attacked in a new colony.

• Added a new references to the the wild rats and disease page:
  • on trichenellosis in wild rats in the Slovak Republic
  • on Cryptosporidium in wild rats in the UK

• Added a new section on whether the Black Death was really caused by Y. pestis to the wild rats and disease page.
• Added a new references to the the wild rats and disease page:
  • on leptospirosis in wild rats in urban Rome and along the Black Sea in Turkey
  • on trichinellosis in wild rats in Finland
  • on hantavirus in wild rats in France
  • on hepatitis E in wild rats in Japan
  • on salmonella in wild rats in the West Midlands, UK
• Added new references on the arrival of the black rat in the Meditarranean and Europe in antiquity to the history of the Norway rat page.

• Added a new page to the About section:
  • Cricket, Widget and Snip

• Added a new section on my rats to the About page
• Added new pages:
  • Paint and Smudge
  • Cage directions
  • Cage expansion directions

• Added a brief section on difficulty swallowing and choking to the why rats can't vomit page.

• I am sad to say that Widget died on April 9, 2005. He lived to the fine old age of just over 2 years and 8 months. His death was not a surprise... he had been doing well in March and was successfully treated for a respiratory illness, but in April his condition went downhill rapidly. He died peacefully in his cage during the small hours of April 9th. We miss him very much.

• The Rat Behavior and Biology website is two years old today!

• Added a new article: Australian blue rats: a hypothesis, on a possible underlying cause of the bleeding disorder, immune deficiency, and hypopigmentation reported in blue rats in Australia in 2003.

• Added a new article: How soon can female rats conceive after giving birth?

• Added a photograph of of Bobbin's whiskers to the world through a rat's whiskers page

• Added a diagram of migration of neural crest cells to the dumbo rat mutation and human analogues page.

• Added new content and references to the dumbo rat mutation and human analogues page.

• Added a new section to the what do rats see? page on whether tiny eyeglasses would help rats see better.
• Added a new article on the dumbo rat mutation and human analogues.

• Added a new anecdotal account of domestic rats establishing a colony in the wild to the wild rats in captivity, domestic rats in the wild page.

• Added new reference to the rat bite fever section of the wild rat disease page, regarding the recent deaths of two people from rat bite fever.

• Added photographs of the assembly of the new Martin's cage to the Martin's cage overview page.

• Added a new article: Martin's cage overview.

• Added a new article: New baby rats, with photos of the three new rats.

• We brought home three new baby rats today!

• Added a new article: How do rats choose what to eat?

• Added a new article on rat rigor mortis.

• My computer has been experiencing technical difficulties over the last month -- regular updates will resume shortly.

• I am very sad to say that Cricket died on September 18, 2004. He was nearly two years and two months old. He died peacefully in his cage. He was a friendly, gentle companion and we miss him very much.

• Added a new quiz: Norway rat or roof rat?

• Added a new funny page: Courses from Rat University.

• Cricket, Widget and Snip are two years old today. Added a new page to the album with pictures of them on their second birthday.
• Added new references and content to the aggression page on the role of odor cues.

• Added a new article on wild rat bites.

• Added two new photographs to the glossary of a bound and a pin.

• Added four new photographs to the glossary of a defensive kick, a belly-up roll and two pushes.

• Added a new article: hearing with whiskers.

• Added a new section to the wild rat behavior page on the mortality of wild rats in a protected, semi-natural enclosure.
• To the wild rats and disease page, added two new sections:
  • diseases and parasites of wild rats in a semi-natural enclosure
  • parasites of wild rats in rural regions of Croatia

• Added a new article: how old is a rat in human years?
• Added a new article: the rat's pubic symphysis.
• Updated the rat weight chart.

• Added a new article: what does neutering do?
• Added a new study to the rabies section of the wild rat disease page, on the extremely low incidence of rabies in wild rats in the United States.
• Added a new study to the tumors and spaying article, showing that spaying greatly reduces the incidence of mammary tumors in female rats.
• Added more information and references to the aggression page, on the effect of an intruder's age at castration on aggression by a resident rat.

Added two new maze articles:

• Rats and mazes: article on some different types of mazes and what they're used for.
• Paper and pencil mazes: mazes you can print out and run yourself.

• Added a new interactive page, the Rat Maze Simulator.

• Added a new article: What is my rat doing? FAQ.

• Changed the title of the website to "Rat Behavior and Biology."
• Added information about the aggressive behavior of wild rats in captivity to the wild rat behavior page
• Added more information to the description of resident rat aggression toward an intruder to the aggression page.
• Added new section about how wild and domestic rats interact in the wild rats in captivity, domestic rats in the wild page.

• To the aggression page, added:
  • More information and references about the effect of social experience on aggression
• Rewrote some sections of the hybridization page for clarity.

• To the aggression page, added:
  • New section on the role of odor cues

• To the aggression page, added:
  • new section on the effect of prior experience of residents with intruders on resident aggression
  • new section on spaying and aggression

• To the aggression page, added new content and references. Specifically:
  • Added new paragraph to the "resident age and aggression toward intruders" section
  • Added a new paragraph to the "who attacks intruders?" section.
  • Added new section called "effect of other rats on male aggression" with subsections for presence of females, nursing young, and juveniles.
  • Added a new section on aggression toward humans.
  • Added more information on the role of the home cage.
  • Broke the "description of resident aggression" into subsections depending on duration of the encounter.
  • Added a section on the impact of an escape chamber on male aggression toward intruders
  • Moved the "home cage" discussion to the intruder section.
  • Reorganized the "castration and aggression" section
• Added a new entry, tail carrying, to the glossary.

• Added a species distribution map of wild Norway rats in California, courtesy of California Wildlife Habitat Relationships System.

• Added more information on Boice's (1977) study of domestic rats in an outdoor enclosure to the wild and domestic rats page, and to the digging section of the Norway rat behavior repertoire page.
• Added a new page with the specifications for a glass-sided digging box.
• Added a new mutation to the coat types page: ragged (rg).

• Added more content to the communal nesting in Norway rats page, on the advantages of birth synchrony.

• Added more content and references to the Norway rat aggression page, on the effect of the presence of females on male aggression.

• Added a description of a new study to the Norway rat aggression page: a longitudinal study of dominance in a mixed-sex colony of rats (Adams and Boice 1983).
• Added two new stats to the biological statistics of the Norway rat page: age at emergence from the burrow, and age at social maturity.

• Added new references and content to the coat color, temperament, and domestication of Norway rats and deermice.

• Added a new article, why do rats pee everywhere?, which is an illustrated, easier version of the urine marking in Norway rats page. The urine marking page wasn't getting much readership. I'm hoping a more approachable version will get the information through better.
• Added a new product, the harness and beeper set, to the rat products page.
• Combined and rewrote the sections on hooded, spooting lethal, and white spotting on the coat color mutations page.

• Added more information and references to the rat vision page, on retinal damage and lens fiber anomalies in albino rat eyes.
• Added another section to the urine marking page on the marking of food.

• Added a new article, rat products, to the rat humor section.
• Added more content and references to the aggression article.

• Added a new entry to the glossary: drag (another rat)
• Added a new subsection to the maternal behavior section of the Norway rat behavior repertoire, on wild vs. domestic maternal behavior.

• Added a new article: are rats right-handed?
• Added new content to the tumors and spaying article.

• Added a new term to the glossary: the crawl over.
• Added more information and references to the conspecific urine marking section.

• Added a new article on aggression in Norway rats.
• Added a new section on paternal behavior to the norway rat behavior repertoire. 

• Added more content and references to:
  • the rat hearing page, on albinism and hearing
  • the communal nesting page, on how nursing by older young damages a pregnant mother's teats
  • the rat vision page, on depth perception using motion parallax cues

• Added a new page to the humor section: the Rat-English Dictionary

• Added a new article: communal nesting and nursing in the Norway rat.
• Added two new glossary entries for communal nesting and communal nursing.
• Added a new section on age and aggression to the Norway rat behavior repertoire.

• Updated the weight chart of my three rats
• Added new references and content to:
  • Rat vision page
    • on the density of ganglion cells in the rat retina.
    • on the rat's field of binocular vision
  • Rats and mice page
    • on muricide

• Changes to the wild rats and disease page:
  • Reorganized the "do wild rats carry diseases and parasites?" section
  • Added some new references

• Added a photo album to the rat humor section called rat photo album. Contains about 35 photos of my three rats in chronological order.

• Added a new story to the humor section called Nutcracker.
• Added three new photographs of Snip hissing to glossary

• Home page redesign:
  • Added search box
  • Added navigation bar at top
  • Placed articles into a big table instead of a big list
  • Reduced font size
  • Eliminated short descriptions of each article
  • Eliminated underlining on links
  • Cropped and shrank photo
• Added new country homes to the rat real estate page

• Added a search box to the top of every page
• Added a new page to the humor section, rat real estate
• Divided the humor section into four sub-categories: rat art, interactive, spoofs, and stories.

• Added a new entry to the glossary: sniffing

• Cricket has painted a new painting, Joyous Spring, and I've added it to the Paw Painting page. You can see how it was done at Rats on Canvas.
• Added a new section on depth perception using motion parallax to the rat vision page.
• Added a new entry to the glossary: the head bob.

• Added new content and references on visual orientation to the rat vision page

• Added new sections to the rat hearing page on:
  • Pinpointing a source of sound
  • Hearing and albinism
• To the rat vision page:
  • Added a new photograph of what an albino rat might see in bright light
  • In the light of new evidence, slightly modified the sample photographs

• Anne's Rat page is one year old today!!
• Added a new movie to the Rat Cam page, from the perspective of an albino rat.

• Added a new page called Rat Cam. The page showcases a short movie from a rat's perspective.

• Added several new species to the why rats can't vomit page.

• Added a new drawing to the the difference between rats and mice page.
• Added a new section on the natural habitat of the wild rat to the wild rat behavior page.

• Added explanatory figure to ultrasonic pest repellers section of the what do rats hear? page.

• Added three new explanatory figures to the are rat-mouse hybrids possible? page.
• Added a new drawing of a rat and mouse to the difference between rats and mice page.
• Changed the contact information to a "ratbehavior" email account.
• Rewrote the what do rats hear? page and added a new section on ultrasonic pest repellers.

• Added seven new explanatory figures to the are rat-mouse hybrids possible? page.

• Added a new article on the anatomy of the rat's eye

• Added a new article: do rats have a dry bite?
• Added new content and references to:
  • porphyrin page, on the onset and duration of porphyrin production
  • infanticide page, on the association between vitamin B12 deficiency, vegetarianism, and pup cannibalism
  • why rats can't vomit page, on vomiting in squirrel monkeys and the inabiligy of Japanese quail and guinea pigs to vomit
  • biological statistics page, on the timing and measurement of male rat puberty.

• Added new figure on rat and human fields of vision to the what do rats see? page

• Added a new photograph of a cup-shaped nest to the glossary.

• Added new references and information on night blindness in albino rats, the effect of age on the rat retina, and a conclusion to the what do rats see? page.

• Anne's Rat page now has its own domain name! http://www.ratbehavior.org/

• Added new section on the albino rat's impaired sense of smell to the rat's world of smell page.

• Added new section on infanticide and maternal age to the infanticide page.

• Added a new section on maternal aggression to the norway rat behavior repertoire

• Rewrote the coat color, temperament and domestication page. Added a lot more content and references. Split off and expanded the technical experimental evidence into its own page with a separate sheet for tables.

• Added a new page, Rat Laundry, to the rat humor section. This page was inspired by a fun thread on the Ratlist in late January 2004. The Rat Laundry page is a joke, of course.

• Added a new section to the wild rat behavior page on wild rat burrows.
• Extended glossary entry for nestbuilding.

• Added more new content and references to the infanticide page.

• Updated the rat weight chart.

• Added more new content and references to the infanticide page.
• Added a drawing of a breeding deme to the wild rat behavior page.
• Added new section on parental behavior to the Behavior Repertoire.
• Added new entries to the glossary:
  • infanticide
  • predatory attack
  • nursing posture
  • pup retrieval

• Added new content and references to the infanticide page.

• Added new figures and content to the rat teeth page.
• Added new entries on the timing of tooth development to the biological statisics of the Norway rat page.

• Added new story about free range time, called on this winter morning, originally written a year ago in December 2002.

• Added copyright, contact, and URL information to the bottom of each page.
• Reorganized the agonistic behavior section of the Behavior Repertoire.

• Added a new story to the Rat Humor section, Rats and Eggshells, about the rats' first experience with a hard boiled egg.

• Added new entries on rat puberty and menopause to the biological statisics of the Norway rat page.
• Added to the glossary page:
  • Short video of a rat eye boggling
  • Two still photos of a rat eye boggling

• Added a new article: why rats can't vomit, on rat stomach anatomy and how it prevents rats from throwing up, how rats defend themselves against toxins anyway, and a bit on the evolution of vomiting.
• Added entries for pica to the Norway rat ethogram and glossary.

• Added a new section on the function of ultraviolet vision to the what do rats see? page 

• To the are rat-mouse hybrids possible? page, added:
  • photograph of chimeric mouse
  • discussion of house mouse/Asian mouse chimeras

• Added a new article: are rat-mouse hybrids possible?

• Added new "where am I?" navigation bar to the top of each page.

• Added a new article on infanticide.

• Added two new articles on ammonia and mycoplasma infections:
  • The main article is called dirty cages aggravate mycoplasma
  • I also added a summary of the original research article for the curious
• Created a new subheading: Rat Health Notes. This section is not going to be a comprehensive overview of rat health, which is a massive topic already well-covered by other websites. However, I've written a few articles on various rat health topics, and needed somewhere to put them, and the Rat Biology subheading was getting too crowded. So, new subheading it is. This new section contains the articles on tumors and spaying and male rat weight that used to be in the Rat Biology section, as well as the new articles on ammonia and mycoplasma. The white blazing and megacolon article is linked from this subheading as well, though I also left a link in Rat Biology: Coat Color section, as it really belongs to both categories. Updated all the navigation bars.
• Made all the titles and bylines the same size.
• Added more information and references to the rabies section of the wild rats and disease page, on the incubation period of rabies in various species.

• Added a new article on biological statistics of the Norway rat: Table of basic rat biology data (life span, weight, developmental milestones, physiological measurements etc.), including definitions of some of the terms and measures.
• Added information on substrains and the genealogy of laboratory rat strains to the Rat species, strains, breeds and varieties page
• Added more information and references to the rabies section of the wild rats and disease page on the incidence of rat rabies in Thailand, and the progression of rabies in rats after infection.
• Updated the rat weight chart.

• Added a new article, tumors and spaying, on the incidence of mammary and pituitary tumors in female rats, the impact of spaying, and issues for the pet rat owner. This article was based on a post to the Ratlist mailing list on October 29, 2003.
• Created a new subheading: Rat Systematics. This new section contains all the articles on rat species and classification that used to be under the general Rat Biology section, as well as the History of the Norway rat page which used to be in the Wild Rat section. All navigation bars have been updated.
• Added a new section on primates and humans to the Why are rat testicles so big? page.
• Added a photograph of a gnawed pen to the gnawing entry of the glossary page.
• Modified the Rat or Mouse Quiz so it works on Netscape.

• Added a new article on the anatomy of rat claws.
• Added a new photograph of scent marks under a black light to the journey into a rat's world page.

• Added a new photo to the porphyrin page.
• Added more information on the rat's perception of color to the What do rats see? page.

• Added microphone and recording specifications to the Norway Rat Vocalizations page.

• Added a new article, Why are rat testicles so big? on rat testicle size and sperm competition.

• Added a new article, rats under a black light, with photographs of rats and their enviornment under ultraviolet light.

• Added a new section to the wild rat diseases page on rat bite fever.

• Added a new section to the rat-mouse page on the response of mice to rats.

• Added a new article, those red tears: porphyrin and the Norway rat, on porphyrin and the Harderian gland in the Norway rat.

• Added two photographs to the urine marking page.
• Added a new section on whisker loss to the the world through a rat's whiskers page.

• Updated and added information to the albino section of the what do rats see? page. Specifically, added new sections on the albino rat's impaired vision in low light and delayed dark adaptation.

• Updated and added new information to the world through a rat's whiskers page. Specifically, added a new section on whisker growth, and updated and expanded the information on the consequences of whisker loss.

• Clarified a few points regarding the agouti gene on the coat color, temperament and domestication page to clear up some confusion:
  • added the "Note" at the end of the agouti section
  • provided an internal cross-link to the wild rats in captivity, domestic rats in the wild page
  • expanded on and added several references

• Added a new article on rat teeth.
• Added a new article: History of the Norway rat. This article was created from the history sections of the "Rats and Mice: what's the difference?" page and the "Wild Nowray rat behavior" page. These history subsections were removed, combined, and expanded to create the new article.

• Added a new photograph and explanatory text to the rat tails page.
• Added a section on the history of the Norway rat to the wild Norway rat page.

• Added a new article, rat tails, on the anatomy and functions of the rat's tail.
• Added a new section on reproductive behavior to the Norway rat behavior repertoire

• Added a new paragraph to the urine marking page on whether urine marking is territorial.

• Added new weights to the rat weight chart.

• Reorganized the rats and mice: what's the difference? page

• Added new information to the wild rat diseases page on whether wild rats carry mycoplasma. This new evidence shows that wild rats have indeed been found with Mycoplasma infections.
• Clarified and added more information to the wild rats and rabies section of the wild rat diseases page.

• Added a new piece to the rat humor section, the mouse's tale, a translation of Lewis Carrol's famous poem into alt.adjective.noun.verb.verb.verb usenet format, originally written in 1996.

• Added a new entry to the glossary page on behavioral estrus.

• Added a new article: Urine marking in Norway rats: what it is, what causes it, and why rats do it.

• Added new entries to the rat behavior glossary: overmarking, flank marking
• Separated my own observations from the description of rat agonistic behavior.

• Added new entries to the rat behavior glossary: lordosis, solicitation, and ear wiggling.
• Added new entry on wild rat disease page: do wild rats carry rabies?

• Added two new pictures to the touch section of Journey into a rat's world.

• Updated and revised the Rat Vision article, adding new information and photographs.

• Added a new article: Journey into a rat's world, that describes and illustrates how a rat might perceive its world -- through its vision, whisker touch, smell, and hearing. Includes photographs of the world as it might be seen through a rat's eyes, and of the textures and scents it might detect.
• Added a new photo of a nestbox entrance under nestbuilding in the glossary.

• Added a new article called Taxonomy of rodent pets, on the scientific classification of the most commonly kept rodent and rodent-like pet species.

• Added a quiz called rat or mouse? that lets you test your ability to tell photographs of rats and mice apart.
• Added a new section on differences between rats and mice to the Rats and mice: what's the difference page.

• Added new section on muricide (mouse-killing behavior in rats) to Rats and mice: what's the difference?
• Added new section on predatory behavior to the Norway Rat Behavior page.
• Added a new entry to the glossary page: Feeding.

• Added new article: Rats and mice: what's the difference?

• Added new article: Why do some rats have white blazes and megacolon?

• Added a summary paragraph to Rat species, strains, breeds and varieties

• Added a spoof song, 88 Lines about 44 Rats, originally written in 2000 using the names and stories of rats who currently belonged to members of the ratlist.

• Added new article: Can a Norway rat and a black rat interbreed?

• Added a new article: Rat species, strains, breeds and varieties.

• Added photograph of a defensive bite to the glossary page

• Changed the Norway Rat Vocalizations page to be more bandwidth-friendly
• Added sound file size to the Norway Rat Vocalizations page

• Added several new coat type photographs to the where do different rat coat types come from? page:
  • Fuzzy
  • Curly-1
  • Curly-2
  • Shaggy

• Expanded description of the various effects of fuzzy gene in hairless rats in the where do different rat coat types come from? page.

• Added a new painting to Paw Painting by Rats, in which Cricket elaborates on the rat-human bond.
• Added several new coat type photographs to the where do different rat coat types come from? page:
  • shorn
  • nude
  • rex
  • wavy
  • kinky

• Added a new painting to Paw Painting by Rats, in which Cricket displays his skills using his tail as a paintbrush. His efforts are recorded in a new Behind the Scenes page devoted to his second painting.

• Added a new page, Paw Painting by Rats, in whichWidget, Cricket and Snip show off their artistic talent with paint. Also visit Behind the Scenes to see photos of the grand masters at work.
• Added photo of Widget holding and eating a yoghurt drop to the glossary page.

• Added new article on rat coat types: how hair is produced, and how mutations in this process cause different coat types, such as hairless and curly coats: where do different rat coat types come from?

• Reorganized the coat color mutations page so that the pigment primer and mutations are organized from largest scale to smallest scale (from cell migration to pigment synthesis) instead of the other way around (smallest to largest). I think this new organization may be clearer.

• Added a new illustrated story, Peas, peas peas, to the rat humor section.
• New photos added to the glossary page:
  • Snip scratching
  • Cricket holding and eating a pea

• Split the wild rat behavior and biology page into two pages: the wild rat behavior page and a new wild rats and disease page.
• Added a new example of a feral rat colony on the wild rats in captivity, domestic rats in the wild page.

• Added a navigation bar to the bottom of each page
• Added a second layer of web pages beneath the main page in order to aid navigation
• Added a summary to the wild rat behavior and biology page.
• Added an introduction to the wild rats in captivity, domestic rats in the wild page
• Added a brief intro to the main page

• Several changes to the wild rat behavior and biology page
  • Expanded discussion of agonistic behavior
  • Reorganized the section on mating systems around population density
  • Added new section on rat social systems
  • folded the section on burrows into the social system section.

• Added new article on wild rats in captivity, domestic rats in the wild.
• Added new section on wild rats on the main page.
• Several changes to the wild rat behavior and biology page
  • Added new section on parasites and behavior
  • Expanded discussion of diseases
  • Added a section on population growth and recovery

• Added new article on wild rat behavior and biology.

• Added image of hooded and normal rat fetuses, showing days on which the migrating melanoblasts reach the various points of the epidermis, to the Where do rat coat colors come from? article and the Norway rat Coat Color, Temperament, and Domestication page.

• Expanded the discussion of the dilute mutation in rats.

• Added new weights to the Male Rat Weight Chart
• Added a new chart of individual rat weights on the Male Weight Page

• Added new photo of Widget Chasing Cricket
• New glossary entries for dorsal immobility response and tonic immobility along with photos.

• Expanded the definition of hissing
• Expanded discussion and definition of urine marking
• Expanded discussion of mutations that cause red hair in mammals (the MCR1 section at the end of the Agouti discussion).

• Split the definition of the rat "run" into trot and gallop.

• Expanded discussions of rat locomotion and gnawing and chewing on the Norway Rat Behavior Page, and added an explanatory figure.
• Created new section on gnawing in the Glossary
• Expanded the discussions of bruxing, chewing and chattering in the Glossary

• Added new weights to the Male Rat Weight Chart

• Added five explanatory diagrams to the Pigment Primer section of the Where do rat coat colors come from? article.

• Added new mutation, red-eyed dilution, to article Where do rat coat colors come from?.

• Added new article entitled: where do rat coat colors come from?

• Additions to the Norway Rat Vocalizations page:
  • Three new chatters by Widget
  • Sequence of three short squeaks by Widget
  • Chevron-shaped short squeak by Widget
  • New Squeak-churr by Snip
  • Sequence of three long squeaks by Snip
  • Sonogram of distress ultrasonic vocalizations by Snip
• Added to description of agonistic behavior on the Norway Rat Ethogram page.

• Added new sensory article: "Tasting Food"

• Added new sensory article, "the rat's world of smell"
• Added short reference to rats hissing during conflict

• Added new sensory article, "the world through a rat's whiskers"

• Added new sensory article "What do rats hear?"

• Posted article "What do Rats See?" originally written in 2001.
• Added new article on rat coat color, temperament, and domestication.

• Added scanned drawings of rat play fighting from Pellis & Pellis (1987) to the Norway Rat Behavior Page and the expanded Rat Play page:
  • Play fighting in young rats
  • Sequence of play fighting in young rats, with repeated attempts to attack and defend the nape
  • Breaking free of a nape hold with a lateral movement
  • Serious fighting sequence in adult rats: sidling attack on flank
• Posted "A Noodle Adventure," a story with photos about the rats' first exploration of my desk, under Rat Humor. Originally posted to the ratlist on September 26, 2002.

• Major reorganization of the Norway Rat Behavior Repertoire, splitting it into two pages:
  • the original repertoire page now describes and explains rat behavior sequences, and includes a new section on play fighting
  • A new second page is a glossary of behavior terms, containing definitions and photographs.
• Created a separate page with an extended discussion of rat play fighting
• Added photo of Widget scratching
• Added photo of Widget kicking Cricket
• Added photo of Widget pushing Cricket
• Added new vocalization and spectogram (Widget shriek sequence) to the Norway Rat Vocalization Page

• Expanded the discussion of urine marking
• Created this Updates page.

• Launched the Anne's Rat Page website with:
  • Anne's Rat Page homepage
  • Norway Rat Behavior Repertoire: behavior descriptions with photographs.
  • Norway Rat Vocalizations: rat sound recordings, spectograms and descriptions
  • Free range time with Widget, Cricket and Snip: illustrated story of an evening of free range time with the boys, originally written on March 6, 2003 and posted to the Ratlist mailing list. Original inspiration for the Norway Rat Behavior Repertoire.
  • Pet Brick FAQ: spoof FAQ on the care and handling of your very own pet brick. Inspired by a series of posts on the Ratlist mailing list on the care of pet bricks. Originally written February 11, 2003 and posted to the Ratlist mailing list files. There were several requests to have the Pet Brick FAQ posted publicly, so I looked into setting up a website for it, and here it is.