easternpipistrellebatThis bat no longer goes by the name 'Eastern Pipistrelle.' This was deemed to be an inaccurate classification. It now goes by the name "Tri-colored Bat' or in scientific jargon the 'Perimyotis Subflavus.' It has been named this because of its distinct tri-coloration on each hair. The hairs are black at the base, with yellow in the middle and then brown at the tips.

This bat species is most common throughout eastern Canada and the eastern parts of the United States. They range as far west as Oklahoma, Kansas and Texas, and run from the Honduras all the way north to southern Ontario. They are the only members of the Perimyotis genus.

Eastern Pipistrelle Life Cycle:

These tri-colored bats will mate during the autumn season. The females will store their mate's sperm during winter hibernation, in their reproductive tracts. They will ovulate in early spring. These bats hibernate either in small groups or alone. After waking from their hibernation, females will form maternity colonies. The colonies are not larger than 20 bats. The males, on the other hand, will roost alone all summer.

The maternity colonies will roost in foliage. They expose themselves to more light than any other species of bat. The gestation period lasts from 44 to 60 days, after which 1 or 2 pups will be born in the month of June. Most all other bat species only give birth to 1 offspring. Each pup only weighs around 20% of the mother's weight.

In the first few days the mother will carry the hairless and blind pups in between roosts. These pups grow very quickly and will be flying within 14 to 21 days. They stop nursing around 4 weeks of age. The males can live as long as 15 years, while the females usually live 10 years.

They feed on small insects and do their hunting at the edge of forests close to open water. They can be dangerous due to their carrying of WNS (White-Nose Syndrome). This disease is very devastating and is responsible for the mass deaths of North American cave bats during hibernation. At the end of 2011 there were an estimated 5.7 - 6.7 million bats killed by this disease in the eastern part of the United States.


Bat rabies has accounted for about 1 human death ever year in the U.S. That causes some people to believe they are dangerous. However, when looked at in another light, dogs (man’s best friend) attack and kill a larger number of people annually than bat rabies.


There are clearly some benefits to sharing a neighborhood with bats. However, as with most any kind of wild animal, it's not a good idea to share your living quarters with them. A lot of bats that enter into living areas are young ones that are lost and only want to find a way to escape. Chasing them out an open window or door is usually an effective remedy. Keeping a leather glove on your hands is recommended if you get close to one. Rabies testing can be expensive and avoiding bites is an easy achievement.

In most cases the exclusion of bats from your living quarters is a simple matter and inexpensive. To exclude them from the entire building can be done although some professional advice may be in order. Over 80% of bat colonies that take up residence in buildings will go undetected by the humans that occupy them. However, large colonies will produce an odor and create noise problems. That is when action is necessary and professional help is warranted.

Protecting Human Living Quarters:

Most bats find their way into human living quarters by entering in through loose-fitting doors, attics, chimneys, open windows or gaps in outside walls. They need a space that is at least 3/4" in diameter or around 3/8" by 7/8" to get in. Room by room searches are recommended to locate entrances like these.

Holes or crevices can easily be plugged with steel wool or caulking. A chimney can be covered with 1/2" cloth screening. Your loose-fitting doors can be fitted with new draft guards. Bats do not chew holes like rodents will, so excluding them is easier. Even if you are unable to exclude them from attics or walls, they can still be kept out of your living areas.

Associated Species:

The predators that hunt the Eastern Pipistrelle are hawks, raccoons, owls and occasionally snakes. There have been 13 feral cats documented as congregating outside of a mine entrance at dusk in order to prey upon these bats as they leave their hibernaculum.

The Eastern Pipistrelle shares its hibernacula with other species of bats. Some of these include the northern long-eared bat, the little brown bat, the big brown bat, and the Indiana bat. They rarely, if ever, form clusters with other species of bat. There has been no competition between these bat species documented.


One of the biggest threats to the Eastern Pipistrelle aside from the WNS (White-Nose Syndrome) mentioned above, is wind power. The wind turbines have proved to have a fatal impact on a broad range of bat species. The wind turbine blades kill the bats through direct impact or by the pressure differential created by the spinning blades. This pressure differential will cause the bat's lungs to fill up with fluid when it gets too close. This phenomenon has been labeled as 'barotrauma.' It kills bats instantly.

Alliance Pest Services is your New Jersey bat removal and control expert. For all your bats and dropping clean ups, call today for an evaluation.