Each of her young is ready to mate in two months. Two mice starting to breed on New Year's day could theoretically have as many as 31,000 descendents by December 31. Though bats are hated and feared, they may also be the single best controller of the insect kingdom. Bats may eat as many as 600 mosquito-size insects in an hour. It takes only 3 weeks for a young rat or mouse to start creating as much damage as their parents.
Rodents can enter a building through a half-inch hole.
It's important to seal openings and cracks around pipes and wires and to fix damaged screens and doors.