Playing the Defensive (Sex) Organ
Some hawk moths have a rather unusual reaction when they hear bats. They start shaking ... their genitals.
Bats find insects using a clever technique called echolocation. They emit very high, ultrasonic sounds and then listen to the reflections (echoes) to estimate where their prey is. That way they know exactly where to attack. This works as long as they don’t go after some types of hawk moths, because research suggests that they have found a way of defending themselves.
Mimicking echolocation sounds
Scientists have long known that some tiger moths could mimic ultrasonic sounds that are similar to the echolocation sounds produced by bats. Two researchers have now discovered that hawk moths can do this as well.
The researchers went on a “hawk moth hunt” in Borneo and placed the captured moths in front of an ultrasonic speaker. They played the moths some pre-recorded bat sounds. When the hawk moths heard this, they began to produce ultrasonic sounds themselves.
Playing the defensive (sex) organ
The moths’ behaviour was recorded by a high-speed camera and special microphones. When the researchers analysed the video recordings, they discovered how the moths did this: both males and females were rubbing scales on their genitals against their bodies to create ultrasonic sounds.
The scientists suspect that the hawk moths use these ultrasonic responses as a form of self-defence. Perhaps they are intended to startle or warn the bats, or even interfere with their echolocation. In any case, they have learned how to play the (sex) organ!