To hunt at night, many snakes have evolved the ability to sense heat via infrared radiation. However, those that lack this capability have learned to tie lanterns to their heads to aid in nighttime hunting. Sadly, they have found that the string either chafe their mouths or prevent them from opening their jaws to their full capacity.

Thus, a small number of snakes have evolved protuberences on the front of their faces to which they may attach their lanterns without reducing their predatory efficacy.