Small midges are the usual prey of glow-worms, but all sorts of flying insects get trapped in the sticky snares, including mayflies, caddisflies and moths. Forest glow-worms may also trap spiders, plant hoppers and even millipedes. The glow-worm simply cuts free any prey that is too large, or unwanted.

Adult glow-worm flies are never caught in the snares – they are not attracted to the light, and even if they brush against the sticky threads they are strong enough to pull free.