A Moment of Science

A Hearing Test for Moths

Despite the fact that they don't communicate through sound, some moths have ears. Find out why on this Moment of Science.

A Moth being held by a person

Photo: Emily Hoyer (flickr)

When bats hunt at night, they use sonar, or sound waves, to find their prey. The sound waves bats send out are too high-pitched for us to hear, but they're heard loud and clear by moths with ears.

Moths aren’t the noisiest of creatures. They actually don’t make sounds at all – unless you count thudding against a screen on a summer night. But despite the fact that they don’t communicate through sound, some moths have ears.

Why would a moth have ears, if not to converse with other moths? Ears allow moths to listen for the approach of one of their greatest predators – moth-eating bats.

Sound Waves

When bats hunt at night, they use sonar, or sound waves, to find their prey. The sound waves bats send out are too high-pitched for us to hear, but they’re heard loud and clear by moths with ears.

Bats are incredibly adept at avoiding even tiny obstacles like twigs – and at honing in on prey – by listening to the echoes that bounce back from these solid objects. Moths with ears can detect this skillful predator even from a distance – and try to get away. Moths without ears, on the other hand, are more likely to become dinner.

Hunting

Here’s how you can conduct a test to see whether moths in your neighborhood have ears. The only equipment you’ll need is a set of keys. After you’ve spotted some moths fluttering around a light or screen, jangle the keys nearby. In addition to the jangling, the keys will emit high-pitched sound you can’t hear – much like the sounds predator bats make when they’re hunting.

Moths with ears will dive away from the sound, as if to escape a hungry bat. Moths without ears won’t react at all. But at least this time, they won’t be dinner.

Stay Connected

What is RSS? RSS makes it possible to subscribe to a website's updates instead of visiting it by delivering new posts to your RSS reader automatically. Choose to receive some or all of the updates from A Moment of Science:

Support for Indiana Public Media Comes From

About A Moment of Science

Search A Moment of Science