Lamp moths warn bats with sonar

For 65 million years, bats and lamp moths have been engaged in an aerial arms race: bats detect and capture lamp moths through echo positioning, and lamp moths use flight strategies and their own ultrasound to evade bats. Scientists have long wondered why some lamp moth species release these high-frequency ticks. They sound like the sound of a creaking floor. Do these sounds interfere with the bat's sonar, or are they warning that the bat tiger moth is poisonous?

To find out the truth, scientists have collected two types of lamp moths: the red-headed moth (pictured) and the lichen moth. Subsequently, they removed the organs that make noise from some of the moths. On a patch of grass in Arizona, the researchers set up infrared cameras, ultrasonic microphones and ultraviolet light, in which UV light is used to attract bats.

In the darkness, they released one lamp moth at a time and recorded the interactions between the moth and the bat. Studies have found that lamp moths rarely produce ultrasonic ticks fast enough to interfere with bat sonar. At the same time, in the absence of a vocal organ, 64% of red-headed moths and 94% of lichen moths are caught.

These findings, published in the U.S. Public Library of Science General, suggest that these species do not interfere with bat sonar like some lamp moths, but warn predators that they are poisonous by shrinking the organs that make sounds. (Xu Xu)