Little Brown Bats (Myotis lucifugus)

little brown bat

Physical Description

The little brown bat is considered a small to medium sized bat that reaches lengths of 3 ½ inches with a 10-inch wingspan. Their upper body is a medium to yellowish-brown and the belly is a light gray to yellowish brown color. Their fur is also glossier fur in comparison to other bats. They also have long toe hair that extends past the toes.

Range in Which They Are Found

The little brown bat has a native range that stretches from central Alaska and Canada, south through much of California, central Arizona, through the Rocky Mountains, and down into Mexico. They are also seen through most of the southeastern United States as well. The southern Great Plains and the southeast Coastal Plains is largely void of their presence.

Presence in Kentucky

These bats are found throughout the state, but it is centralized to particular areas. They are going to gravitate to heavily forested areas during their active summer periods and areas with proper hibernation caves in the winter. There are some who will winter in Kentucky and spend their summers further north and ones who winter farther south will spend summers in Kentucky.

Habitat and Behavior

The little brown bat was thought to be tree-dwellers before people moved in and have since adapted well to the presence of people. This species is the one that is most encountered by people because of their extensive range. They are a migratory species who will travel north of their summering range and south to hibernate for the winter. They prefer to hibernate in caves, mines, and underground quarries. The warmer, moister areas of the caves are where they will hibernate. They will do this solitarily in rows or in small, loose clusters.

In the warmer weather, they will prefer to roost in buildings, barns, under bridges, in tree cavities, and under loose bark. They are foraging generalists who will hunt in a wide range of places like forest edges, stream corridors, parks, and even yards.

Maternity colonies will form just after hibernation and can be as large as a few hundred females and their juveniles. They birth a single pup in June, and they are flying 3 weeks after birth. Some males have been seen roosting with the females, but most of them will separate themselves.


These are a species that is known to be threatened by the condition known as white-nose syndrome. This is a fungal infection where a white, fuzzy fungus will grow on their faces. It has been seen resulting in an unprecedented amount of death in the populations of the northeastern United States.

Key Takeaways

  • Little Brown Bats have small size and flexible wings for precise flight maneuvers.
  • They can be found in various habitats, including forests, wetlands, and urban areas.
  • Little Brown Bats primarily feed on insects, using echolocation to locate prey.
  • Conservation efforts should focus on preserving and restoring roosting habitats, reducing pesticide use, and addressing habitat loss and climate change for their long-term survival.

Physical Characteristics

The Little Brown Bat (Myotis Lucifugus) exhibits distinct physical characteristics that distinguish it from other bat species. These characteristics are essential for its survival and successful adaptation to its environment. One of the most notable physical features of the Little Brown Bat is its small size, with an average wingspan of only 8-9 inches and a weight of 7-9 grams. This compact size allows the bat to maneuver quickly and efficiently through complex environments, such as dense vegetation and narrow crevices.

Behavioral adaptations are also evident in the physical characteristics of the Little Brown Bat. The species has evolved long, flexible wings that enable it to perform intricate flight maneuvers, such as tight turns and rapid changes in direction. This ability is crucial for catching flying insects, which make up the majority of its diet. Additionally, the bat’s elongated fingers and thin, membranous wings allow for precise control during flight and efficient capture of prey.

Furthermore, the Little Brown Bat possesses exceptional echolocation capabilities. It emits high-frequency sounds that bounce off objects in its environment, allowing it to navigate and locate prey in complete darkness. Its large ears and intricate auditory system are specially adapted to receive and interpret these echoes, providing the bat with detailed information about its surroundings.

Understanding the physical characteristics of the Little Brown Bat is essential for conservation efforts. By appreciating and protecting its unique adaptations, we can contribute to the preservation of this remarkable species and the delicate ecosystems in which it thrives.

Habitat and Distribution

Little Brown Bats (Myotis lucifugus) can be found in a wide range of habitats across North America. These adaptable bats have been observed in various environments, including forests, woodlands, wetlands, and even urban areas. They often roost in natural structures such as caves, rock crevices, and tree hollows, but they can also take advantage of man-made structures like buildings and bridges.

Habitat loss poses a significant challenge for Little Brown Bats. Deforestation, urbanization, and the destruction of caves due to human activities have led to a decline in suitable roosting sites. Additionally, the use of pesticides in agriculture negatively impacts their prey availability, further threatening their survival.

Migration patterns of Little Brown Bats are not well understood. While some populations are known to migrate long distances, others exhibit a more sedentary behavior, remaining in their preferred habitats year-round. It is believed that migration is influenced by factors such as food availability and temperature. As bats face increasing challenges due to habitat loss and climate change, understanding their migration patterns becomes crucial for their conservation.

Conservation efforts should prioritize the preservation and restoration of suitable roosting habitats for Little Brown Bats. This includes protecting natural structures and creating artificial roosting sites in areas where suitable habitats have been lost. Additionally, reducing the use of pesticides and promoting sustainable agricultural practices can help ensure an adequate food supply for these bats. By addressing the issues of habitat loss and understanding migration patterns, we can contribute to the long-term survival of the Little Brown Bat population.

Feeding Behavior

Feeding behavior of the Little Brown Bat is influenced by its habitat and prey availability. These bats are insectivorous, meaning they primarily feed on insects. They are active at night and use echolocation to locate their prey. Little Brown Bats employ various foraging strategies to maximize their feeding efficiency.

One of the foraging strategies utilized by Little Brown Bats is called “gleaning”. This involves capturing insects directly from surfaces such as leaves, branches, or the ground. Another strategy is aerial hawking, where the bats fly through the air and catch insects on the wing. They are agile flyers, capable of capturing prey in mid-flight.

Prey selection is an important aspect of the feeding behavior of Little Brown Bats. They prefer to feed on soft-bodied insects, such as moths, beetles, and flies. These insects provide a high energy yield, which is crucial for the bats’ survival and reproduction. However, their diet may vary depending on the availability of prey in their habitat.

To further illustrate the feeding behavior of Little Brown Bats, the following table highlights their foraging strategies and preferred prey selection:

Foraging Strategies Prey Selection
Gleaning Soft-bodied insects
Aerial Hawking Moths, beetles, flies

Understanding the feeding behavior of Little Brown Bats is essential for their conservation. By studying their foraging strategies and prey selection, conservationists can better assess the impact of habitat loss and insect population decline on the survival of these bats. This knowledge can help inform conservation efforts aimed at protecting their habitats and ensuring their continued existence.

Reproduction and Life Cycle

Reproduction and life cycle of the Little Brown Bat is intricately linked to their foraging strategies and prey selection. Courtship behavior plays a crucial role in the reproductive success of these bats. Mating usually occurs in the fall, with sperm storage occurring in the female’s reproductive tract until spring. Females typically give birth to a single pup each year, usually in early summer.

Parental care is another important aspect of the Little Brown Bat’s reproductive strategy. The female bat will nurse and care for the pup until it is capable of flying and foraging on its own. This period of maternal care lasts around four to five weeks.

The life cycle of the Little Brown Bat involves a combination of migration and hibernation. During the summer months, these bats will establish maternity colonies in buildings, trees, or caves, where females give birth and raise their young. As the weather turns colder, the bats will migrate to hibernation sites, such as caves or mines, where they will enter a state of torpor to conserve energy. This allows them to survive the winter when insects, their primary food source, are scarce.

Understanding the reproductive and life cycle of the Little Brown Bat is crucial for conservation efforts. Protecting their roosting and hibernation sites, as well as ensuring the availability of suitable foraging habitat, is essential for the survival of this species.

Conservation Status and Threats

The conservation status and threats faced by the Little Brown Bat (Myotis lucifugus) are of paramount importance in ensuring the survival of this species and maintaining their crucial ecological role. Human impact has been a significant factor contributing to the population decline of these bats.

One of the major threats to the Little Brown Bat is habitat loss. As human populations expand, forests are cleared for urbanization and agriculture, resulting in the destruction of roosting sites and foraging areas essential for the bats’ survival. Additionally, the use of pesticides in agriculture poses a threat to their food sources by reducing insect populations.

Another significant factor in the decline of the Little Brown Bat population is the spread of white-nose syndrome (WNS). This fungal disease has decimated bat populations across North America, causing widespread mortality. The fungus disrupts hibernation patterns, leading to increased energy expenditure and decreased survival rates.

Climate change is also impacting the Little Brown Bat population. Rising temperatures and changing weather patterns affect the availability of food resources and disrupt the bats’ ability to navigate and find suitable roosting sites.

Conservation efforts are crucial in mitigating these threats. Protecting roosting sites, preserving natural habitats, and implementing sustainable agricultural practices can help create a more favorable environment for the Little Brown Bat’s survival. Additionally, monitoring and research on WNS and its effects are essential for developing effective management strategies. By addressing these threats, we can ensure the survival of the Little Brown Bat and maintain the important ecological functions they provide.

Bat Species

Rafinesque’s big-eared bat (Corynorhinus rafinesquii)
Silver-haired bat (Lasionycteris noctivagans)
Seminole bat (Lasiurus seminolus)
Indiana bat (Myotis sodalis)
Virginia big-eared bat (Corynorhinus townsendii virginianus)
Red bat (Lasiurus borealis)
Gray bat (Myotis grisescens)
Eastern small-footed myotis (Myotis leibii)
Evening bat (Nycticeius humeralis)
Big brown bat (Eptesicus fuscus)
Hoary bat (Lasiurus cinereus)
Southeastern myotis (Myotis austroriparius)
Northern bat (Myotis septentrionalis)
Eastern pipistrelle (Pipistrellus subflavus)

Bat Related Diseases

White-Nose Syndrome

Nuisance Bat Topics

Bat Removal

Frequently Asked Questions

What does a little brown bat look like?

Little brown bats are the most abundant bat in North America, weighing about ½ ounce and measuring 3 ½ inches long when full grown. They have well-furred bodies with naked, transparent wings. Their wings are a membrane spread across their elongated fingers. They primarily hunt insects in the air and while crawling on the ground may catch beetles, crickets, and other insects[3].

Where do little brown bats live?

Little brown bats are commonly found roosting in buildings and may find their way into attics and walls of homes. They are known to leave their summer roost sites starting in August, and the colony will have moved to winter habitat by October. Occasionally, if the weather remains above 40 degrees during the day, big brown bats may stay active into November and even December[1].

What do little brown bats eat?

Little brown bats primarily hunt insects in the air and while crawling on the ground may catch beetles, crickets, and other insects. They are known to consume a large number of insects, playing a significant role in controlling insect populations[3].

What is the most abundant bat in North America?

The little brown bat is the most abundant bat in North America, known for its small size and insect-eating habits. It is a crucial species for controlling insect populations[3].

Citations: [1] [2] [3] [4] [5]