Brown Bat on Wall: Species and Physical Characteristics
The brown bat often seen resting on a wall belongs to the genus Eptesicus, with the big brown bat being the most common species in North America. These bats have a wingspan of 32 to 39 centimeters and weigh between 15 and 26 grams, according to the Bat Conservation International. Their fur is dark brown, and their wings are dark brown to black, making them easy to identify when perched on a wall.
Brown bats are nocturnal and use echolocation to navigate and hunt insects. A single big brown bat can consume up to 1,000 mosquito-sized insects in one hour, based on data from the National Science Foundation. They typically roost in buildings, under bark, and in rock crevices, and they are known to return to the same wall roosting spots year after year.
Legal and Regulatory Framework for Brown Bats on Walls
In the United States, the big brown bat is not listed under the federal Endangered Species Act, but some other bat species are protected. The U.S. Fish and Wildlife Service enforces rules that can restrict the removal of bats from walls during certain seasons to protect maternity colonies. Property owners should consult local wildlife agencies before removing a brown bat from a wall.
State-Level Protections and Permits
Many states have additional regulations that apply even when federal protections do not. For example, the U.S. Fish and Wildlife Service notes that some states require a permit to handle or exclude bats from structures. These rules aim to balance property concerns with conservation goals, and violations can result in fines or legal action.
Economic and Ecological Impact of Brown Bats Roosting on Walls
Brown bats provide significant pest control services. A 2011 study published in Science estimated that insect-eating bats save U.S. corn farmers alone more than $1 billion annually in pest control and reduced pesticide use. When a brown bat roosts on a wall near agricultural areas, it can directly contribute to lower crop damage and chemical costs.
For homeowners, a brown bat on a wall can indicate a nearby colony, which may lead to guano accumulation and potential structural concerns. Professional exclusion services typically cost between $300 and $1,500, depending on the size of the colony and the complexity of the job, according to industry data reported by the Forbes home improvement network. Preventive measures such as sealing entry points and installing bat houses can reduce future roosting incidents.