Understanding rodents

Mice and rats have tremendous breeding potential. One female mouse can give birth to 5-10 litters per year, yielding five to six young per litter. The gestation period is a mere 19-21 days. These babies are sexually mature in 6-10 weeks. The average female mouse lives to 9 months of age.

Under ideal situations, a pair of rats and their offspring can produce 20,000,000 young in 3 years. One female rat is capable of producing another 22 breeding females in 1 year (assuming a 50:50 male/female ratio of offspring), which mature within 3 months.

Rats and mice have poor eyesight but excellent senses of smell, taste, touch and hearing. They do not like open areas and prefer contact with walls and other objects. They do not range far from the nest. The range for rats is up to 45 m (148 ft), for mice 9 m (30 ft). Rats are extremely apprehensive about new objects and will avoid them for several days. Leaving a trap or bait station out for about 5 days is necessary to ensure acceptance. Mice quickly accept new objects. These tendencies become very important when designing baiting or trapping programs.