Roost disturbance and heat stress may cause bats to take wing during daylight hours. During the day, they roostCsingly, in pairs, in small groups, or in large concentrations, depending on the species. They seek out dark, secluded spots such as caves, hollow trees and rock crevices. They hang upside down, by their feet. In fall, winter and early spring, insects are not readily available to bats in Pennsylvania and other northern states.
Bats are true hibernators.
Throughout winter, they eat nothing, surviving by slowly burning fat accumulated during summer. Bats can be roused fairly easily from hibernation, and often are able to fly 10-15 minutes after being handled. Most favor cave zones having the lowest stable temperature above freezing. During winter, bats may awaken and move about within a cave to zones of more optimum temperature. In many caves, bats of several species hibernate together.