Can You Hear White Nose Syndrome?

February 15, 2026

Pennsylvania Game Commission has gone to tripod-mounted microphones, also known as bat detectors to listen for White Nose Syndrome among bats. These bat detectors are placed outside caves where bats are known to hibernate during the winter months. These detectors then listen for bats flying outside caves.

The detectors were normally used during summer months to track bat activity but have become a great asset for tracking bats during the winter months. The bat detectors listen for and record the echolocation calls of bats, which bats use to avoid obstacles or to pursue flying insects in the dark.

Bats emit what is known as a stream of ultrasonic clicks which is their biological sonar which bounce back from objects and then bats are able to track their pray or avoid objects. These ultrasonic clicks or frequencies are beyond what the human hearing can hear but the bat detectors can pick up these clicks. The detectors then convert these sounds into audible sounds and with software are converted into visual display to be read.

What does all this mean? It means that biologists can listen to the bats activity without entering caves where bats hibernate during the winter and chance disturbing bats winter sleep to check for WNS. During winter months bat activity at the caves entrance way should be non-existing as bats should be hibernating. As summer approaches this activity should pick up as bats become more active and search for food and head to their summer roosts.

In caves where bats with WNS is present show bat activity during the winter months, but normally no bat activity should be present. So by using these bat detectors biologist are able to track WNS all year round with non-invasive monitoring. This avoids waking bats during the winter months and a possibility of causing more harm to the bat population.

Categories: Bats, White Nose Syndrome (WNS)