Bats at a Glance

Article and photo by Neil Marchington
Added Content and Updated August 14, 2025, by Jeff Taylor

  • Bats are mammals that nurse their young while hanging upside down
  • Every bat in Oregon eats insects, and only insects.
  • Bats use no energy to hang upside down. Dead bats can continue to hang from cave ceilings for many years after they die.
  • The largest bat species in Central Oregon can weigh up to one ounce. The Townsend Big-Eared bats, common in local caves, weigh about a half ounce at the most.
  • Bat bones are hollow
  • Local bats have been known to live 30 years or more, which is very unusual for such a small mammal.
  • Bats are estimated to benefit agriculture by many billions of dollars a year in the U.S. by consuming pest insects. Some estimates place this figure at over $50 billion. A moderate-sized roost of bats can consume over a million insects a year.
  • Less than 1% of bats are rabid. An average of about 2 people a year die in the U.S. of rabies (not all are bat-related), making the danger posed by bats extremely low.

We are visitors to their homes

Many people think of bats when they think of caves. Bats are incredible animals and often misunderstood by people. Often, bats encountered in caves are disturbed by the invasion of their homes. During times like hibernation or maternity, disturbances may lead to the death of these important animals. Some bat species spend the majority of their lives in caves. Other common roosts include trees, buildings, bridges, rock crevices, and mines.

Before visiting a wild cave, please check our Cave Access page for current closure information. If you encounter bats, please leave the area to avoid disturbing them. Disturbance during hibernation or maternity periods may lead to death for the bats. A bat coming out of hibernation early can lose 10% of its body weight during a single disturbance.

This Section of the Article was Updated on August 14, 2025, by Jeff Taylor

Additional Information About Bats in Oregon

Diversity of Oregon’s Bats

Oregon is home to 15 species of bats, all of which are insectivorous. Common species include:

Townsend’s Big-Eared Bat (Corynorhinus townsendii) – Known for its large ears and preference for undisturbed roosts.

Little Brown Bat (Myotis lucifugus) – Once common, now threatened in parts of North America due to White-Nose Syndrome.

Hoary Bat (Lasiurus cinereus) – A migratory species often seen in forested areas.

Each species has unique roosting and foraging habits, but all play a vital role in controlling insect populations.

Bat Conservation Challenges

Bats face a number of threats in Oregon and across North America, including:

  • Habitat loss from development, logging, and mine closures.
  • White-Nose Syndrome (WNS) – A fungal disease that has killed millions of bats in the U.S. and Canada. While not yet widespread in Oregon, it poses a serious risk.
  • Disturbance in caves during sensitive periods like hibernation or maternity.
  • Pesticide use reducing insect prey and harming bats directly.

Why Bats Matter

Bats are one of nature’s most effective pest control agents. A single bat can eat hundreds of mosquitoes in an hour, and large colonies can protect crops from destructive moths, beetles, and other insects. Their role in maintaining healthy ecosystems is irreplaceable.

How to Help Bats

  • Respect cave closures and seasonal restrictions. Central Oregon caves close for bats between October 1 to April 30.
  • Avoid handling bats — if one is found injured, contact a licensed wildlife rehabilitator.
  • Install bat houses to provide safe roosting habitat.
  • Reduce pesticide use to protect bat food sources.
  • Educate others about the importance of bats and dispel myths.

Safety Around Bats

While the risk of rabies is extremely low, it’s still important to never touch a bat with bare hands. If you find a bat on the ground or in distress, contact Oregon Department of Fish and Wildlife or a local rehabilitator for guidance.

Remember: When we enter a cave, we are guests in the homes of bats and other wildlife. By minimizing disturbance and practicing responsible caving, we help ensure these remarkable animals continue to thrive in Oregon’s high desert and beyond.