In most states, it is illegal to harm or exterminate bats. The most effective and humane way to get rid of bats is with a one way valve (bat cone or bat valve). The bat cone allows a bat to safely leave your attic but it prevents reentry. Seal all potential entry points before installing a bat cone.  

Finally, you cannot start bat exclusion if flightless pups are present in your attic. The pups are completely dependant on their mothers.  Abandonded pups in your attic will die. 

Throughout the year, bats move to different locations that each serve a distinct purpose.  A bat maternity roost is a place where a large group of pregnant females gathers to raise their babies. 

Bat maternity colonies begin to form in early April. In the late spring or summer, homeowners who see bats leaving an attic or overhang at twilight may need to check for an infestation. The best time to remove a bat maternity colony is after the pups can fly (typically starting in August). 

The cost for bat removal varies. There ar ea number of factors that determine the cost such as: how long bats have been roosting, how big the colony is, how many potential entry points are on your house, and how much damage needs to be repaired. 

Bats have furry bodies that range in color to include shades of tan, red, brown, and grey. To compensate for their poor eyesight, bats typically have large ears designed for echolocation. As the only mammals capable of flight, they are very light and have wings. The bone structure of the wing resembles that of a human hand, as there are flaps of skin between the bones.

At their tiniest, bats grow between 2.5 to 3.5 inches (6 to 9 cm) in length and have a wingspan of about 8 inches (20 cm). Larger species range from 7 to 8 inches (18 to 20 cm) in length and have a wingspan between 21 and 23 inches (53 and 58 cm).

Highly adaptable, bats set up roosts in a variety of environments like deserts, woodlands, suburbs, and urban areas. They are found around the world and only avoid extreme climate zones like the polar regions or especially harsh deserts. While bats prefer warm temperatures, they survive in temperate environments by hibernating come winter months. Bats will use barns, attics, caves, tree cavities, and the undersides of bridges to roost and/or overwinter.

Are bats known to enter homes or yards?
For the most part, bats are innocuous because they are nocturnal and humans sleep through their activity. However, in order to survive cold winters in various regions of the world, bats enter homes and roost in secluded locations like attics. They can squeeze into openings as tiny as a quarter of an inch (6 mm) in diameter, such as cracks around windows and doors, pipes and electrical wiring that lead inside, and vents.

While bats are beneficial creatures overall, they do pose certain health threats. Diseases like rabies and histoplasmosis are often associated with bats. Though 99 percent of rabies-related deaths are caused by rabid dogs, bats are still carriers of the disease. Thankfully, even rabid bats refrain from biting humans unless they feel threatened in some way.

One of the biggest risk from a bat infestation is bat guano. The accumulation of guano can stain ceilings, walls, and floors. Left unchecked, guano can also lead to structural damage in your attic.

While the fungus that causes histoplasmosis is not carried by bats, it lives in warm, humid soil. Bat droppings act as a catalyst for the development of the fungus, and human infection occurs when people inhale the spores.

Bats also host ectoparasites, like fleas, flies, ticks, and mites, that endanger the health of humans and pets. Finally, bat urine can cause a pervasive and unpleasant smell, while bat droppings stain ceilings and building visages.

Since bat populations can prove beneficial, some homeowners construct what are known as bat houses close to gardens and around homes in order to keep bats from roosting where they are unwanted. Since bats will likely still target any available structure, homes remain susceptible unless individuals take the time to seal off potential points of entry. In addition to sealing cracks and openings, illuminating attic spaces and eaves during nighttime hours helps deter bats from roosting, as does placing fans in attics to lower the temperature.

It is unlikely homeowners insurance will cover the cost of bat removal. However, your insurance may cover the repairs associated with a bat colony.