Bats are the only nocturnal mammals that fly and they are a very diverse group of animals. There are basically two kinds of bats out of the 1200 species that abound; the colonizing bats or solitary bats.
Colonizing bats come in 4 major species:
Little Brown Bat (Myotis lucifugus)
Appearance: Its fur has a glossy look and is a uniform dark brown with a slightly pale greyish color underneath. The adult bat measures between 2-4 inches long and weighs between 5-14 grams with a wingspan membrane that measures 22-27cm. Female bats are larger than the males.
Biology/Life Cycle: The females are sexually mature from 7-9 months, while male bats mature at 1year. Mating occurs in the fall and the female bat will sometimes delay the fertilization of the egg till spring time. They give birth to the young in early June or late August. Young bats are unable to fly until they are a month old. On average, the bat lives for 6-7 years and some live beyond 10 years.
Habitat: The little brown bat is known for three different roosting sites: day roosts (trees, buildings, caves, rocks), night roost (same places as day roosts but are more constrained as they are sometimes packed together for warmth) and hibernation roosts.
Diet: The little brown bat loves to eat insects, mosquitoes, moths, beetles, wasps and other insects. They hunt in packs, foraging for insects using echolocation, and often catching their prey mid-flight. During the day, they often enter into a near hibernation state called torpor, which means slowing the body rate while sleeping to conserve energy and emerge to hunt at night.
Behavior: The little brown bat sleeps in caves and mines during the day and hunts by night. They are fast creatures and can form very large colonies. Brown bats are usually common in older buildings.
Big Brown Bat (Eptesicus fuscus)
Appearance: Its body coloration varies from light brown to dark brown and can sometimes have reddish hues. However, the face, ears, wings and tail are black with no fur. This bat weighs between 14-16 grams, measures between 4-5 inches in length, and has a wingspan of 13 inches. The big brown bat has sharp and heavy teeth and the females are slightly larger than the males.
Biology/Life Cycle: Big brown bats mate from November through March. The female gives birth in early June through August. Male bats habitually live longer than the females with average life span of 19 years.
Habitat: They are commonly seen in the suburbs and urbanized areas, visiting homes, barns, churches etc. Here, they roost in hollow trees and caves.
Diet: They are fond of eating beetles and other insects like moths, flies and wasps.
Behavior: These bats are nocturnal, social and migratory animals. They all roost together except when the mothers are taking care of their young ones. They hibernate in winter and utilize echolocation to avoid obstacles and capture their prey.
Brazilian Free-Tailed Bat (Tadarida brasiliensis)
Appearance: They are medium sized bats with brown furs, big ears, and with long, narrow and pointed wings that span about 11 inches. The tail goes past the skin to the animal’s wings.
Biology: Free-tailed bats breed once a year. After mating in spring, the females birth their babies after 11-12 weeks. Birthing takes place upside down and lasts about 90 seconds. The females become sexually matured at nine months and the males at two years. Life span is from 7 to 12 years.
Habitat: They can be found in North and South America, living in caves, bridges and attics. They roost in hollow trees and hang upside down to sleep or rest.
Diet: They eat insects like moths, beetles, dragonflies, ants amongst others.
Behavior: They are social animals that live in colonies, and communicate by calling, squeaking and body movements. They usually fly in a quick straight line and at a higher altitude than other bats. These bats start searching for food after sunset and continue till deep in the night. They are more active in warm weathers.
Evening Bat (Nycticeius humeralis)
Appearance: Dark brown coloration, except for its black ears, the evening bat weighs between 6-14g and measures 86-105mm in length. Its wingspan is 260-280mm and it is often confused with small and big brown bats.
Biology: Females live in separate colonies from males and a male can mate with up to 20 females. The female stores the sperm until spring, when ovulation occurs. The young are born in hollow trees, buildings and attics. Young bats fly from 3 weeks and males leave the roost after six weeks. Evening bats live for 2-5 years.
Habitat: They prefer to live in the forest and are often called forest bats. They do not live in caves.
Diet: They eat insects like other bats
Behavior: They touch and use their scents to find each other. They also use echolocation to find their prey.
Go back to the Bat Removal
Bat exclusion methods
How to get bats out of the house
How to inspect a building to find bat entry holes
bat removal instructions
How to remove bats from the attic
How to remove bats from a chimney
How to trap bats - bat trapping
How to clean bat guano
Species of colonizing bats
How to catch a bat
How to kill a bat
What If You Are Bitten By A Bat
About Colonizing Bats