No they don't. They kill any crocodiles that enter their territories. Crocodiles and lions have been known to kill babies. Why Crocodiles don't eat Hippos? David Kirshner's answer to Why do crocodiles not attack hippos? read more
crocodile have no bounded to live only in water but it is about all species of crocodile that these live near water and can stay more time in water their nostrils are also to breath while floating sub surface of water. these prefer water for living, because of fishes to eat. read more
In turn, beyond cases of killing the seldom unguarded hippo calf, very large Nile crocodiles have been verified to occasionally prey on "half-grown" hippopotamuses and anecdotally perhaps adult female hippos. Also, aggregations of crocodiles that have been seen to dispatch still living bull hippopotamus that have been previously injured in mating battles with other bulls. read more