Big Brown Bats

About Big Brown Bats

Big brown bats (Eptesicus fuscus) are one of the most common bat species in North America. These nocturnal mammals play a crucial role in controlling insect populations, particularly by feeding on agricultural pests and mosquitoes. Big brown bats are resilient and adaptable, thriving in both urban and rural environments. They are known for their strong flight and echolocation abilities, which they use to navigate and hunt in the dark. Despite their beneficial impact on ecosystems, big brown bats can become a nuisance when they roost in human structures.

What Do Big Brown Bats Look Like?

Big brown bats are medium-sized bats with a wingspan of about 12 to 16 inches and a body length of around 4 to 5 inches. They have glossy, dark brown fur on their backs and lighter, grayish-brown fur on their undersides. Their broad wings are hairless and leathery, adapted for agile flight. Big brown bats have a large head with short, rounded ears and a blunt nose. Their teeth are sharp and well-suited for their insectivorous diet. These physical characteristics, along with their robust build, make them easily identifiable among bat species.

Facts About Big Brown Bats Gestation

Big brown bats have a reproductive cycle that begins in the spring. After mating in the fall, females store sperm over the winter and fertilize their eggs in the spring. The gestation period lasts about 60 days, resulting in the birth of one or two pups, usually in late May or early June. Newborn bats are born blind and helpless, clinging to their mothers for warmth and nourishment. They begin to grow fur within a few days and open their eyes at about two weeks. By four to five weeks, the young bats are capable of flight and start foraging independently. Maternity colonies, where females raise their young, are often found in warm, secluded areas.

Big Brown Bats Habitat and Behavior

Big brown bats are highly adaptable and can be found in a variety of habitats, including forests, fields, urban areas, and agricultural lands. They roost in trees, caves, and buildings, often selecting warm, dry locations such as attics, barns, and bridges. Big brown bats are nocturnal and use echolocation to navigate and hunt insects during the night. They emit high-frequency sounds that bounce off objects, allowing them to detect prey and avoid obstacles. Their diet primarily consists of beetles, moths, and flying insects. Big brown bats hibernate in the winter, often in sheltered locations like caves or abandoned buildings, where they remain inactive until spring.

What Are 5 Unique Facts About Big Brown Bats?

1. Big brown bats can consume up to half their body weight in insects each night, making them effective natural pest controllers.
2. They use echolocation to navigate and hunt, emitting ultrasonic calls and interpreting the returning echoes.
3. Big brown bats have a lifespan of up to 20 years in the wild, although many do not survive their first year.
4. They are capable of flying at speeds of up to 40 miles per hour, showcasing their agility and hunting prowess.
5. Big brown bats enter a state of torpor during hibernation, significantly lowering their metabolic rate to conserve energy through the winter.

What Are the Problems Related to Big Brown Bats?

Big brown bats can become problematic when they roost in buildings and other human structures. Their presence can lead to noise disturbances, particularly at dusk and dawn when they are most active. Accumulated bat guano and urine can create unpleasant odors, stain surfaces, and pose health risks due to the potential for fungal growth, such as histoplasmosis. Bats can also introduce parasites like mites and fleas into homes. Structural damage is another concern, as bats can squeeze through small openings to access attics and walls. Managing these issues requires effective exclusion and cleanup strategies to ensure a safe and bat-free environment.

What Are the Risks Associated with Big Brown Bats?

The primary risks associated with big brown bats involve health hazards and property damage. Bat guano can harbor the fungus Histoplasma capsulatum, which causes histoplasmosis, a respiratory disease that can affect humans and pets. Inhaling spores from disturbed guano can lead to severe respiratory issues. Additionally, bats can carry rabies, although the incidence is low; a bite or scratch from an infected bat can transmit the disease. Structural damage can occur when bats roost in buildings, as they can squeeze through small gaps and create entry points. Their presence can also attract secondary pests like bat bugs, mites and fleas. Effective management and exclusion are necessary to mitigate these risks.

Get Rid of Big Brown Bats Treatment

To get rid of big brown bats, start by identifying and sealing non-active entry points around your home, such as gaps and holes in the roof, eaves, and walls. Use bat-proofing materials like heavy-duty mesh or caulk to block these access points. Install one-way exclusion devices over active entry points.  These allow bats to exit but prevent re-entry. Avoid bat removal during the maternity season (May to August) to prevent trapping young bats inside. Clean up guano and disinfect affected areas while wearing protective gear to avoid exposure to harmful spores. For large infestations or complex exclusion needs, hire a professional wildlife control service to ensure safe and effective bat removal.

Big Brown Bats Prevention Advice

Preventing big brown bat infestations involves regular maintenance and vigilance. Inspect your home for potential entry points and seal them with durable materials. Install chimney caps and cover vents with fine mesh to prevent bats from entering. Maintain screens on windows and doors to keep bats out. Trim tree branches that hang over or near your house to reduce access points. Use outdoor lighting strategically to avoid attracting insects, which can draw bats. Educate family members about the benefits and risks of bats, encouraging them to report sightings. Implementing these preventive measures can help keep big brown bat populations under control and protect your property.