There are 16 bat species that call Alabama home. Bats are the only mammal that can fly. Their bodies are covered in fur and have a membrane that creates a wing. Bats are nocturnal and can be seen flying from dusk until daylight. Bats are beneficial and very valuable in controlling mosquito populations. Some bats can consume up to 3,000 insects every night (half their body weight) Bats also protect crops from insect infestation so some farmers will install bat houses around their fields.
Crevice dwelling bats live in caves, crevices, abandoned mines, and old buildings. Foliage roosting bats will roost in trees year round. Very few species of bats will live in structures such as houses or bridges (Batworld.org)
Bats will migrate each year to warmer climates or hibernation areas. In the spring bats will migrate back to their summer roosts. How far will a bat migrate? They can migrate from a few miles to hundreds of miles.
The little brown bat is one of the the most common bats in Alabama. It is a medium size bat being 3-4 inches long with a wingspan of 8-10 inches. Females will gather in nursery colonies every year that can be as large as several thousand bats. The little brown bat occupies three different roost types; day, night, and hibernation. Typically the day and night roost sites are buildings, under rock and piles of wood.
Big Brown Bat is another very common bat in Alabama. They average 4-5 inches long with a wingspan of 12-14 inches. Since the big brown bat prefers cooler temperatures it can tolerate conditions that most bats cannot. Because of this most big brown bats are not migratory and use the same roost for both summer and winter. Like the little brown bat, females will gather in nursery colonies to birth and raise their young.
Evening Bat is a common bat in Alabama that will roost in structures. The evening bat is 3-4 inches in length with a wingspan of 10-12 inches. This species of bat resembles a small big brown bat. Like the little brown bat and the big brown bat females will give birth in nursery colonies. The evening bat is seldom found in caves and prefers to roost in hollow trees, buildings and attics.
There are 13 other species of bats in the state but these are the most common found in structures