BASIC RODENT BIOLOGY

Rats and mice are both capable of transmitting disease to humans through their hair, droppings and urine. A single mouse can excrete 40 to 100 droppings per day, according to the Mallis Handbook of Pest Control by Arnold Mallis. ..

Rats and mice might also bite, although it is not common. Sometimes a bite can result in rat-bite fever, a potentially fatal disease if not treated. Some people develop an allergic reaction to the excrement of rats or house mice, which can cause asthma-related symptoms.

In addition to causing disease, food contamination by rats and mice can cause billions of dollars in damage. Between one-fifth and one-third of total food production is lost annually due to rat contamination according to Mallis, who also states that a single rat can consume about 1 ounce of food per night. Some rat colonies can harbor more than 100 rats..

Rats and mice are also successful breeders. A female rat can reproduce every three weeks, and usually gives birth to about six to 10 young at one time. A female mouse reproduces every three to four weeks and usually gives birth to about five or six young, although sometimes up to 12. This means that both rat and mice colonies can grow large quickly, although rats only live for about a year. Mice can live up to two or three years under ideal conditions.