Bats are often found in urban landscapes. The two most common species in Wisconsin are the little brown bat and the big brown bat, and both can be found roosting in buildings and bat houses in summer. These are the most likely species to come in contact with people and pets. These species form colonies and have their babies in warm sites such as attics, barns and bat houses. Bats in Wisconsin are insectivores and can eat their body weight in insects each night. They will not chew their way into buildings, but may exploit holes created by squirrels or woodpeckers. Though uncommon, bats can carry rabies, so avoid any contact whenever possible.