Bats Need Your Help!

What is White Nose Syndrome?

White-nose syndrome is a disease caused by the fungus Pseudogymnoascus destructans. The disease is estimated to have killed over six million bats in eastern North America since 2006, and can kill up to 100% of bats in a colony during hibernation.

In March 2016, Washington’s first case of white-nose syndrome was confirmed in a Little Brown Bat (Myotis lucifugus) near North Bend, 30 miles east of Seattle. Though the disease has devastated bat populations in eastern North America, we do not yet know how it will impact western bats.  In general, bats in Washington do not hibernate in large aggregations like bats do in eastern North America.  Thus, the spread of the disease in western North America may be different.

The fungus can grow on the nose, wings, and ears of an infected bat during winter hibernation, giving it a white, fuzzy appearance. Once the bats wake from hibernation, this fuzzy white appearance goes away. Even though the fungus may not be visible, it invades deep skin tissues and causes extensive damage.  Affected bats arouse more often during hibernation which causes them to use crucial fat reserves, leading to possible starvation and death. Additional causes of mortality from the disease include wing damage, inability to regulate body temperature, breathing disruptions, and dehydration.

The fungal disease is spread primarily through bat-to-bat contact. Bats can also contract the disease from an environment where the fungus is present. People can carry fungal spores on clothing, shoes, or recreation equipment that has come in contact with the fungus.  Appropriate decontamination for clothes and equipment used in areas where bats may live is critical to reducing the risk of spreading this catastrophic bat disease.


Bats Need Your Help

  • Whenever possible, avoid entering areas where bats may be living to limit the potential of spreading the disease. Do not allow dogs to access areas where bats may be roosting or overwintering as they may act as carriers of the fungus to new sites.
  • Avoid disturbing bats in winter and at maternity colonies whenever possible.
  • People who come into contact with areas where bats live, including crevices in rock cliffs, buildings, talus areas and talus caverns, caves or mines should clean their equipment and clothing immediately afterward.  Whenever possible, use the decontamination protocol available at
  • Improve bat habitat and construct homes for bats. Reduce lighting around your home, minimize tree clearing, and protect streams and wetlands. For more information on living with bats, and instructions for how to build a bat house, visit:



Bats are valuable members of ecosystems around the world, saving farmers in the U.S. alone over $3 billion annually in pest control services. One colony of bats can consume many tons of insects that would otherwise consume valuable crops, or threaten human health and well-being. Many species of bats are also valuable for the pollination of plants and dispersal of plant seeds.

Over six million bats are estimated to have died due to this disease over the past few years in the eastern US and Canada, with as much as 100% mortality in some colonies. This disease could possibly lead to the extinction of some bat species.


Reporting Sick or Dead Bats

If you find a sick or dead bat, groups of bats, or bats flying in the daytime, please report your observation here:


Additional Resources