The males have an upturned bulbous and sting-like tail (which is actually their genitalia), hence why they are called scorpionflies, yet they do not sting. The heads have a beak-like appearance, and their wings have slight variations in pattern which was once thought aided in distinguishing the 3 UK species which can be difficult to tell apart. But it is now realised you have to get down to microscopic scrutiny of the genitalia to distinguish them.
Mating usually occurs at night and can be quite dangerous for the male. The female may kill him if things don’t go well, so he gives her a drop of saliva as a present to try and please her before mating is attempted. They feed on dead and dying insects and other invertebrates, and have a crafty way of stealing spider victims wrapped in silk from their webs without getting caught themselves.