
Most things that go into the mouth of the Nile crocodile (Crocodylus niloticus) never come out again. Not so its young. This consummate killer, which grows up to 5.5m long and can easily bite a man in half, is amazingly gentle with its offspring. The female lays up to 50 eggs in a hole, which she covers with soil and guards for 90 days. When she hears high-pitched noises from below she knows it is hatching time and she digs away to help the hatchlings - which look exactly like miniature adults - emerge from their shells. Then she catches them all up in her mouth and, peering out from between the bars of her huge teeth like tiny crocodilian convicts, they are carried to a river to clean themselves. Found throughout sub-Saharan Africa, Nile crocodiles have few enemies other than man but they do occasionally get into fights with hippopotamuses. In a one-to-one clash the hippo will invariably be victor but more often other crocodiles join the fray and win an unequal battle.