Do bats hibernate during the winter or do they migrate to a warmer climate until spring? It depends on the species of bat. Bats that hibernate in the winter are called cave bats, while migratory bats are called tree bats. Each type is named after its preferred roost. In Wisconsin, there are three species of tree bats: the eastern red bat, the hoary bat, and the silver bat. Cave bats in Wisconsin include the big brown bat, the little brown bat, and the northern long-eared bat.

Where Do Bats Go in the Winter if They Are Migratory?

All three species of migratory tree bats from Wisconsin fly to warmer climates during the winter. The hoary bat and the eastern red bat may travel as far south as Mexico, but the silver-haired bat goes no further than the southern United States. Migratory tree bats depart around September or October and return to Wisconsin around April or May.

Wisconsin tree bats are all insectivorous. They fly south where insects are more plentiful in winter when Wisconsin insects have died off or gone into diapause. The hoary bat feeds primarily on moths, while the eastern red bat will also eat beetles and true bugs. The silver-haired bat eats moths, beetles, and flies.

What Do Cave Bats Do During the Winter?

Cave bats go into a state called torpor. It’s not true hibernation because warm temperatures can rouse them, but they can spend weeks or months at a time in an inactive state by slowing down their metabolism to conserve energy. Cave bats roost in large groups in the winter because even though their body temperature drops significantly during torpor, their remaining body heat can help warm one another.

Bats need a roosting place called a hibernaculum to spend the winter. They look for very specific conditions of temperature and humidity when seeking out a hibernaculum. Because a bat’s metabolism slows down when it goes into torpor, it relies on its environment to keep warm. Anything less than about 35 degrees Fahrenheit and the bats could freeze. However, hot temperatures aren’t ideal either because they could use up more energy than their fat stores can provide them.

Bats look for a hibernaculum with a consistent temperature within a range of between 35 and 40 degrees Fahrenheit. They may roost in caves, hence the name, but these spaces can often be too damp for them. Because buildings often provide consistent temperatures and low humidity, bats may make roosts inside barns, churches, and warehouses. Your home’s living space is probably too warm for bats, but the attic or garage may provide ideal conditions.

How Do Bats Get Into Houses?

As bats fly past your house, they can feel streams of hot air that may escape from holes, cracks, or gaps in the exterior. Bats can fit through an opening of only three-eighths of an inch, so they follow the stream of warm air and squeeze their way inside. Bats may roost in the attic, or they may go from there into wall voids. Bats prefer dark, close spaces to roost in, and if the attic doesn’t suit their purpose, the wall voids may be more satisfactory. In either case, bats like to roost as far up off the ground as possible because, while they do fly, they can’t do a standing take-off from the ground as birds do.

Why Should You Call Skedaddle for Bat Removal Madison?

“Why do I need professional bat removal near me?” you may be asking yourself. Bats are protected species and attempts to remove them yourself could violate the law. Our technicians remain in compliance when removing bats from your home. Even if you don’t already have bats, we can identify and close off potential entry points to prevent them from getting in, which is preferable to getting them out. Learn more about our prevent-and-protect services.