Below the water’s surface insects perform unusual behaviors to maintain their advantage for food and space.

The sound producing ridges show up as faint lines in this photo.  Different species have different types of ridges and thus likely produce different frequencies of sound, though yet unconfirmed.

The abundant nets can create competition for space and food.  To protect their territory the larvae use sound produced by rubbing their front legs on grooves under their head.

A net-spinning caddis larva (Arctopsyche grandis) near its shelter.  The net collapses when taken out of the water.

Adult net-spinning caddis.