Hummbug

Hummbug: noun. A rare species of insect which can only be identified by its distinct humming mating call. Hummbugs are excellent at camouflage and so, they have only ever been discovered thanks to their mating calls. The problem is that, after complex scientific research, it has been determined that hummbugs only mate once every 24 years. This is why there are only 4 specimens of the insect in museums worldwide. Three of these are in the Chicago Field Museum and one is in the Entomological Museum of Vilnius.