House Mouse: Belligerent Biology

By Dr. Stuart Mitchell

"When a group of genetically identical mice lived in the same complex enclosure for three months, individuals that explored the environment more broadly grew more new neurons than less adventurous mice, according to a study. This link between exploratory behavior and adult neurogenesis shows that brain plasticity can be shaped by experience and suggests that the process may promote individuality, even among genetically identical organisms." -Science Magazine (May 9, 2013)

Mouse individuality may play a large part pursuant to its adaptability and global survival. Injurious to man, the House mouse, Mus domesticus, is one of the most successfully pestiferous mammals. Commensal (benefit one party) interaction has allowed House mouse to thrive outside its natural environments. Neolithic revolution (agriculture and husbandry) has been essential to commensal evolution.

Along with human global expansion has come species biodiversity erosion. However, House mouse has successfully radiated with human endeavor.

Rodent synanthropy ("together with man") has also radiated the epidemiology of infectious disease. House mouse has both obligate and facultative parasites that can have serious public heath implications. Conversely, the House mouse has been domesticated as an essential biomedical research model.

House mouse thrives under a variety of conditions. Mice are found in and around homes, commercial structures, open fields and agricultural operations.

House Mouse Taxonomy

• Kingdom: Animalia
• Phylum: Chordata
• Class: Mammalia
• Order: Rodentia
• Suborder: Myomorpha
• Family: Muridae
• Genus: Mus
• Species: domesticus

Considerable history exists between humans and mice. The Greeks built a temple to Apollo Smintheu (Mouse god) as appreciation for mice possibly chewing the leather of their adversaries' shields in 1500 BC. During the late Greco-Roman and early Christian eras, parts of mice were included in potions designed to cure sickness.

The Chinese and Japanese have a long history with House mouse. The "Year of the Mouse" is every 12 years. The "Hour of the Mouse" is 11:00am to 1:00pm. The messenger of the "god of wealth" is the mouse.

Living 1.5 to 2.5 years, House mouse is generally non-aggressive (evades vs. confronts). Males housed together will probably fight, sometimes to the death of the opponent. "Barbering" is the phenomenon of focal loss of hair or whiskers with no wounds due to the establishment of hierarchy and defense of territory.

House mice have an adult body length of 3.0 to 3.9 inches (7.5 to 10 cm). Tail length is 2.0 to 3.9 inches (5 to10 cm). Weight is 0.4 to 0.9 ounces (10 to 25 gm). Coloration ranges from white to grey to brown to black (light on underside). Ears and tail present some hair.

Mice hind feet are 0.59 to 0.75 inches (15 to 19 mm) long. Gait is a run with a stride of 1.8 inches (4.5 cm). Vertical jumps can be up to 18 inches (45 cm).

Males and females are not easily discerned. Females have a smaller distance between their anus and genital opening. Females have five pairs of mammary glands. Males have a distinct presentation of testicles that are large compared to the rest of the body (can be retracted).

Find a full description of the house mouse on www.mypmp.net.