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Bats in Ohio – Information and Facts

Bats found inside Cleveland, OH Homes

There are over 1,000 bat species in the world. These bats are divided into two categories. There are tree-dwelling, and cave-dwelling species. In the Greater Cleveland, Ohio region there are two main species that find shelter inside our man-made structures. The Little Brown Bat, Myotis lucifugus, was once the most common and prolific bat in our region. With the outbreak of White Nose Fungus in their winter hibernacula, populations of Little Brown Bats are quickly disappearing. Now it is becoming more likely that you will have Big Brown Bats inside your home than the latter.

These bats are nocturnal predators that feed on night flying insects. They can consume thousands of mosquitoes in a single night. Therefore they are extremely beneficial to have around. Although our bats are slow to reproduce, only having 1-2 pups per year, they are very long lived. 10 or more years is a common lifespan. Some may even live up to 30 years of age! That is only if they do not fall prey to a skunk, raccoon, hawk or an owl. Mice will even prey upon them inside their roosts!

Interesting Bat Facts

Many people think that bats are blind. Although they are color blind, they can see with their eyes. Similar to dolphins, bats are another mammal that uses echo location. High frequency sounds guide their flight help them to detect insect prey. They are unique in the fact that no other mammal on Earth has the ability to fly. Their wings consist of a thin membrane stretched over long finger bones. Contrary to popular belief, bats are not rodents with wings. They are more closely related to shrews and moles, than they are rodents.

True Hibernators

Bats are do not survive well in very cold climates. Most northern species will migrate to more temperate climates during the winter months. Bats can hibernate up to 83 days. Tree-dwelling bats overwinter in leaves, logs, and tree cavities. Cave-dwelling bats will overwinter in abandoned mines, caves and inside buildings. The areas in which they overwinter are called “hibernacula”. These true hibernators undergo physiological and metabolic shutdown that drops their heartbeat from 400 beats per minute to 25 beats per minute. Little Brown Bats hibernate in areas that are not likely to be disturbed. A single disturbance from their winter slumber, expends fat reserves necessary for 67 days of hibernation. Sadly enough, one disturbance can easily lead to death.

Little Brown Bat


The Little Brown Bat, Myotis lucifugus, is a small to medium sized bat. Approximate dimensions are 3″-5″ long and weighing about one-half ounce. Little Brown Bats have an 8″-10″ wingspan. Their fur is russet-brown or grey toned. Their membranes are mostly absent of fur. As a result they have a distinctive black facial mask.


Moths are a large part of their diet, along with aquatic insects. As they forage, they fly about 10- 20 feet above trees and about 3-6 feet above water. They can fly as fast as 20 MPH, repeatedly using the same flight pattern. These bats are generally found in close proximity to bodies of water. Midges, mayflies, and other aquatic insects are a huge part of their diet, along with moths and beetles. They can consume up to 600 insects per hour after emerging shortly after dusk. Interestingly enough, prey can either be caught directly in their teeth, or initially grabbed with their wings or tail. They will feed for 1-5 hours before roosting close together in their night roost. Here they keep warm and deposit fecal matter. Their night roost is often close to their daytime roost.


Primary mating time is in fall. Yet there is a delayed fertilization until they emerge from their hibernacula in spring. They then form nursery colonies of several to over 1,000 females during April and May. While females tend to roost together, males are more solitary. They will roost alone or with a small group of other males.

White Nose Syndrome

Little Brown bats are found in the Northern two-thirds of the United States. While they were once the most common and most prolific bat in the Greater Cleveland area, their species has been recently decimated by disease. White Nose Fungus, present in their winter hibernacula, is quickly putting them into consideration for protection under the Endangered Species Act. Their normal lifespan is around 6-7 years. Yet they can very well live 10 or more years. Now with the White Nose Syndrome, many bats do not emerge from their first winter slumber. Little Brown Bats are not very cold hardy. They require their hibernacula to be a near constant 40 degrees with a high relative humidity. These just happen to be ideal environmental conditions for fungus too. Millions of bats have died from this disease since its discovery nearly one decade ago.

Big Brown Bat

The big brown bat, Eptesicus fuscus, is a large brown bat. At maturity they grow to just over 5″ long. On top of that they have a broad nose and wings, short black ears, with long glossy fur. Commonly found within man-made structures, this species is less tolerant of heat. During May or June 1-2 young are birthed. As they search for cooler temperatures, they will accidentally enter homes through the chimney. Usually big brown bats are solitary or found in small groups. Yet colonies range from 20- 300 bats. This widespread species of bat can survive subfreezing temperatures. As a result, they are not migratory, and can stay within the same roost throughout the entire year. Frequently, they remain active into November and December.