Bats across Indiana are waking from hibernation and moving out of their caves in search of food.

These flying mammals play a vital role in Indiana’s ecosystem and even its economy. Feeding on beetles, mosquitoes and moths, a single bat can eat half its body weight in insects each night, benefitting Hoosiers out for an evening stroll as well as farmers plagued with pests.

Benefits of Indiana’s bats

The Indiana Department of Natural Resources estimates bats save the country’s agriculture industry more than $3.7 billion each year by acting as a natural pesticide. Not only do they protect plants, but bats help propagate them. The bats in the state pollinate plants and spread seeds, helping sustain a diverse ecosystem.

The state is home to 13 bat species, some hanging around in trees while others finding caves and mines for shelter. Most cave bats in Indiana are listed as state endangered animal and face unprecedented death rates due to white nose syndrome. A majority of Indiana’s migratory tree bats are species of special concern.

What cave-dwelling bats are found in Indiana?

Big brown bat: One of the healthiest populations of bats in the state, big browns primarily roost in trees and structures during the winter and find caves, mines and other structures during the winter. These bats feed on insects and have an impressive 13-inch wingspan. (More: animaldiversity.org/accounts/Eptesicus_fuscus)

Gray bat: Listed as a federal and state endangered species, gray bats find summer and winter roosts in caves and mines. The greatest disturbance for these bats are humans disturbing hibernating colonies. (More: animaldiversity.org/accounts/Myotis_grisescens)

Indiana bat: The first recorded Indiana bat was found in the state’s Wyandotte Cave. They’re listed as federal and state endangered, and in the summer roost in trees, and search for caves and mines in the winter. Habitat loss is one of the biggest threats to the species. (More: animaldiversity.org/accounts/Myotis_sodalis)

Little brown bat: These state endangered bats prefer three roosts: day, night and hibernation. These roosts vary depending on the ambient temperature and include anything from buildings and trees to under rocks and in piles of wood. (More: animaldiversity.org/accounts/Myotis_lucifugus)

Northern long-eared bat: These bats are listed as endangered in Indiana and face habitat loss due to timber harvesting. Insecticides are also affecting the food supply. These bats can be found roosting in trees during the summer and caves in the winter. (More: animaldiversity.org/accounts/Myotis_septentrionalis)

Tri-colored bat (pipistrelle): Heavily affected by white-nose syndrome, these bats are listed as a state endangered species. While the individual hairs on these bats are tri-colored, they mostly appear dark yellow. Tri-colored bats roost in trees in the summer and in caves during winter. (More: animaldiversity.org/accounts/Pipistrellus_subflavus)

How has white-nose syndrome affected Indiana’s bats?

In 2009, the year before white-nose syndrome was discovered in the state, biologists counted about 220,315 hibernating bats. By 2020, that number dropped about 17% due to the disease.

Tri-colored bats saw the greatest death rate in that time frame, dropping from a population of 1,163 to only about 100. Little brown bat populations declined 89%, big brown bats dropped 47%, and Indiana bats saw the smallest effects, dropping 15%.

Latest research: White-nose syndrome is killing Indiana bats. Colder caves might save the vital bug eaters

Here’s how to help Indiana’s bats

Installing bat boxes can help provide emergency shelters for bats that might need them when proper roosts are unavailable. Planting pollinator gardens are also going to help bat populations, as they support native insects that help sustain bat populations.

Karl Schneider is an IndyStar environment reporter. You can reach him at karl.schneider@indystar.com. Follow him on Twitter @karlstartswithk

IndyStar’s environmental reporting project is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.