Atherix ibis is a species of 'ibis flies' belonging to the family Athericidae, a small family very similar to Rhagionidae (Snipe Flies). This species is present in most of Europe and in Nearctic ecozone. Adult females aggregate in large clumps and lay egg masses on tree branches or under bridges over flowing waters. In such a way the first stage larvae will fall into the water, where they will start their life cycle. The larvae are predators.