Acoustic jamming...

Acoustic jamming...  Scientists have shown that the long tails of some moth species confuse the echo-location senses of predating bats.  Basically, they're an acoustic jamming system.  The bats end up targeting the moths' tails instead of their bodies, thus saving the moth from becoming a meal for the bat.

I remember first reading about a completely separate defensive mechanism in some moths: they've evolved the ability to hear the bat's “sonar” squeaks, allowing them to take evasive action before the bat can eat them.  This new jamming mechanism with the long tails is a separately evolved defensive mechanism, in different species.  From what I've read, it appears that no single moth species has both defensive mechanisms...