Wingtip folds and ripples on saturniid moths create decoy echoes against bat biosonar.

Sensory coevolution has equipped certain moth species with passive acoustic defenses to counter predation by echolocating bats. Some large silkmoths (Saturniidae) possess curved and twisted biosonar decoys at the tip of elongated hindwing tails. These are thought to create strong echoes that deflect biosonar-guided bat attacks away from the moth's body to less essential parts of their anatomy.