Bats are a diverse group of mammals, with over 1,400 species. They occupy a wide range of environments globally. Their adaptations allow them to thrive in diverse locations, from natural landscapes to human-made structures. Understanding where bats reside offers insight into their ecological roles and remarkable adaptability.
Global Presence
Bats can be found on nearly every continent, adapting to diverse climates and ecosystems. They are absent only from polar regions and a few isolated oceanic islands. Their widespread distribution highlights their evolutionary success.
Tropical regions, particularly in Central and South America and parts of Asia like Indonesia, host the greatest variety of bat species. Abundant food and varied shelter in these warmer climates contribute to higher diversity. Even within countries, diverse environments—from deserts to forests and urban areas—support various bat populations.
Natural Habitats and Roosts
In natural environments, bats use various structures for shelter, known as roosts, which protect them from predators and elements. Caves are frequently used, providing stable temperatures and humidity, ideal for day roosting and hibernation. These underground spaces can include natural caves, lava tubes, and abandoned mines, sometimes hosting colonies numbering in the millions.
Tree hollows, cavities, and crevices in living or dead trees are common roosting sites. These offer shelter and protection; some hollows take over a century to form naturally. Bats do not create these spaces but opportunistically use existing gaps, such as under exfoliating bark or in woodpecker holes.
Some bats, called tree bats, roost in dense foliage, hanging among leaves and branches. These species, like the Eastern red bat, may also use Spanish moss. Foliage roosts are used by solitary bats or small groups, offering less protection from environmental fluctuations than enclosed spaces.
Human-Associated Habitats
As human settlements expand, bats adapt to using various human-made structures for roosting. Attics, barns, and old buildings are common choices, mimicking the shelter and stable conditions of natural roosts. These provide protection and warmth, appealing for raising young. Many of the 47 bat species in the United States, for example, use human structures for shelter.
Bridges are another frequently used human-made habitat, offering sheltered spaces near water sources rich in insect prey. The underside of bridges provides shade and protection from the weather. A notable example is the Congress Avenue Bridge in Austin, Texas, home to a large urban bat colony. Tunnels and culverts also provide suitable roosting environments for some species.
Seasonal and Specialized Roosts
Bat roosting locations change throughout the year, driven by seasonal needs and life cycle stages. During winter, many bat species hibernate in specialized roosts called hibernacula. These are underground sites like caves, mines, cellars, or even attics, requiring cool, stable temperatures just above freezing and high humidity to conserve energy and prevent dehydration. Disturbances during hibernation can be detrimental, causing bats to prematurely awaken and deplete their fat reserves.
In spring and summer, female bats congregate in maternity roosts—warm, protected places where they give birth and raise their pups. These sites are often found in attics, barns, or tree hollows, with females selecting warmer locations to support rapid development of their young. Throughout the night, between foraging flights, bats use temporary night roosts. These locations, less protected than day roosts, serve as resting spots for digestion, grooming, and social interaction, often closer to foraging areas to minimize travel time.