The Egyptian plover and the Nile crocodile have a symbiotic relationship in which the plover feeds on parasites on the crocodile's hide. Although a myth exists that the plover enters the crocodile's mouth unharmed, there is no evidence to substantiate it.
The Greek historian Herodotus first wrote about the supposed safe entry of the Egyptian plover into the Nile crocodile's mouth in 440 B.C. Since then, the myth has persisted, but no reliable researchers have ever observed or photographed the phenomenon, and photographs cited as proof turned out to be fraudulent.
Nile crocodiles do not need their teeth cleaned, as the teeth are regularly replaced throughout their lives. Although leeches on the lips and tongue of crocodiles are problematic, they deal with them by basking with their jaws open to dry the insides of their mouths. Egyptian plovers do, however, feed on parasites on the crocodile's exterior, where the birds can avoid the crocodile's jaws.
Nile crocodiles are apex predators and feed on anything that moves. Mammalian prey includes antelopes, giraffes, buffaloes, wart hogs, lions, leopards and monkeys. They also eat snakes, lizards and turtles. They feed on fish by swimming into schools and jerking their heads sideways. They also eat a number of bird species, such as ostriches, storks, eagles and small flying birds. It is likely that if Egyptian plovers hopped into their mouths, they would consume them rather than tolerate them.