Where Do Bats Roost? Why Do Bats Live In Attics?
Bats spend over half of their lives roosting so where and why bats roost is important to understand the many diverse bat species we have here in North America. Bats are regularly found in trees, caves, under bridges, vacant buildings, and found roosting in an around the attics of homes to name just a few places that bats roost! Bats require a safe roosting place away from predators, severe weather including extreme high and low temperatures. The bat roost always becomes a communication place between bats and where a bat colony would live together to raise their young bat pups, rest and digest their food and hibernate together.
Mouse Click A Photo Below
A Few Of The Bats In The US
- Big Brown Bat
This medium-sized bat ranges from 10–13 cm (3.9–5.1 in) in body length, with a 28–33 cm (11–13 in) wingspan, and weighs between 14–16 g (0.49–0.56 oz). The fur is moderately long and shiny brown. The wing membranes, ears, feet, and face are dark brown to blackish in color.
Big brown bats are nocturnal, roosting during the day in hollow trees, beneath loose tree bark, in the crevices of rocks, or in man-made structures such as attics, barns, old buildings, eaves, and window shutters. Big brown bats navigate through the night skies by use of echolocation, producing ultrasonic sounds through the mouth or nose. They are known also to produce audible sound during flight, a click or a sound like escaping steam.
- Eastern Small Footed Bat
The Eastern small-footed bat is between 65 and 95 millimeters in length, has a wingspan of 210 to 250 millimeters, and weighs between 4 and 8 grams. The bat got its name from its abnormally small hind feet, which are only 7 to 8 millimeters long. The fur on the dorsal side of their body is dark at the roots, and fades to a light brown at the tips, which gives the bats a signature shiny, yellow-brown appearance. The fur on the dorsal side of the body is a dull gray color, which is believed to help camouflage themselves in their hibernacula. The defining characteristic of this bat is its face-mask, which is completely black.They also have black ears, wings and interfemoral membrane, (the membrane between the legs and tail).
- Little Brown Bat
As suggested by the bat’s name, its fur is uniformly dark brown and glossy on the back and upper parts with slightly paler, greyish fur underneath. Wing membranes are dark brown on a typical wingspan of 22–27 cm (8.7–10.6 in). Ears are small and black with a short, rounded tragus. Adult bats are typically 6–10 cm (2.4–3.9 in) long and weigh 5–14 grams (0.2–0.5 oz). Females tend to be larger than males. The fore and hind limbs have five metapodials. The skull of the brown bat lacks a sagittal crest. Its rostrum is shortened and has upslope profile of the forehead. Its braincase flattened and sub-circular when observed dorsally. The bat has 38 teeth all of which including molars are relatively sharp, as is typical for an insectivore, and canines are prominent to enable grasping hard-bodied insects in flight.
- Northern Long Eared Bat
The northern long-eared bat is a small bat, measuring an average of 8.6 cm (3.4 in) in total length, including a tail about 4 cm (1.6 in) long. Adults weigh between 5 and 8 g (0.18 and 0.28 oz). The fur and wing membranes are light brown in color, and the bat lacks the dark shoulder spots found in the closely related, and otherwise similar Keen’s myotis. Compared to other Myotis species, these bats have long ears with a relatively long tragus; when folded forwards the ears extend well past the nose. They also have a longer tail and larger wing area than most comparably sized Myotis bats, giving them increased maneuverability during slow flight.
- Eastern Red Bat
This is a medium-sized Vespertilionid, averaging weights of 9.5–14 g and measurements of 112.3 mm in total length. Adults are usually dimorphic: males have red hair while females are chestnut-colored with whitish frosting on the tips of the fur.
- Hoary Bat
The hoary bat averages 13 to 14.5 cm (5.1 to 5.7 in) long with a 40 cm (15.5 in) wingspan and a weight of 26 g (0.92 oz). It is the largest bat normally found in Canada. Its coat is dense and dark brown, with white tips to the hairs that give the species its ‘hoary’ appearance for which it is named. The body is covered in fur except for the undersides of the wings. The bats can cover an impressive 39 kilometers while foraging.
- Silver Haired Bat
This medium-sized bat is predominately black (including the wings, ears, interfemoral membrane, and fur) with white-tipped hairs. The basal upper half of its tail membrane is densely furred. This gives the bat a frosted appearance and its common name’s sake. This species has a flattened skull with a broad rostrum. This species weighs around 8–12 g, has a total length of ~100 mm, a tail length of 40 mm, and a forearm length of 37–44 mm.
- Tri Colored Bat
This reddish, yellowish and brownish bat is one of the smallest bats in eastern North America. The forearms are orange to red, and the wing membrane is black. Adults weigh between 4 and 10 g and reach a forearm length of 30 to 35 mm. They are easily distinguished from other similar species by their tricolored fur. These bats were renamed by Dr. Paul Cryan with the US Geological Survey.
Bats have both day and night roosting places. The day roosting place is for extended rest periods where the night roosting places are used for brief resting while eating. Over the course of a night, bats may rest more than once at different roosting locations. Some bat species use their night roosts to hunt for prey and in tropical regions, bats species may use them to call potential mates. Bats may change roosts daily when threatened by predators or have different summer (possibly homes or attics) and winter roosting locations (caves).
Bat roosts are chosen because of favorable protection against wind, the temperature and moisture amounts in the roosting area. Most bats roost hanging upside down and unlike humans have evolved to not have all the blood run to their heads. Bats that accumulate in large groups like the Mexican free-tailed bat have evolved so that they are not affected by highly dangerous levels of ammonia from the bat guano in caves from millions of bats roosting in places like Carlsbad Caverns New Mexico.
Not every bat species will choose to roost in vacant buildings and in the attics of homes. Many bat species are content to live in foliage and some of them have fur color to protect them from predators like the Eastern Red Bat that looks like a dead leaf when roosting in trees or under the leaves and foliage of a large tree.
Common bats found in homes include the Big Brown bat, Little Brown Bat and the Brazilian aka Mexican Free-tailed bat . If you have thought you have bats roosting in your home please consider contacting a local bat removal professional from this web site.