Insects in the family Elateridae are commonly called click beetles (or "typical click beetles" to distinguish them from the related families Cerophytidae and Eucnemidae). Other names include elaters, snapping beetles, spring beetles or skipjacks. This family was defined by William Elford Leach (1790–1836) in 1815. They are a cosmopolitan beetle family characterized by the unusual click mechanism they possess. There are a few other families of Elateroidea in which a few members have the same mechanism, but all elaterids can click. A spine on the prosternum can be snapped into a corresponding notch on the mesosternum, producing a violent "click" that can bounce the beetle into the air. Clicking is mainly used to avoid predation, although it is also useful when the beetle is on its back and needs to right itself. There are about 9300 known species worldwide, and 965 valid species in North America.