Butterflies might be experts at using auditory clues to figure out when they’re about to become lunch, according to a new discovery. Butterfly auditory organs are still being figured out; we’ve only known for about a century that they can hear at all. So it was quite a surprise when Kathleen Lucas of the University of Bristol in England found that blue morpho butterflies not only sport tiny ears on the bases of their wings, but can distinguish between high and low-frequency sounds.

Such an advanced ear (above, left) is very rare among similar insects; moths and other butterfly species can hear in a very limited frequency range and take any sound in that range as a threat. Researchers suspect that the blue morpho uses different types of sounds to determine when to stay still (its very visible blue wings are hidden when it’s sitting still) and when to fly. High-frequency sounds, like a bird’s song, are an indication to stay put. Low-frequency sounds, like a bird’s flapping wings, are the blue morpho’s cue to get out of there before it becomes bird food.