 About 33 species are known in one family (Diaphanocephalidae), two genera (Diaphanocephalus and Kalicephalus) and six subgenera.Snakes can be orally infected with third-stage larvae experimentally, but it is a mystery how snakes become infected in the wild.Since snakes flick their tongue around to examine their environment, it is possible that the nematodes attach to the tongue.