A niche is the "job" an animal has in it's community. But also includes relationships with other animals. A hippo has few predators (an animal that kills and eats other animals) but those include lions and alligators. The lions attack the hippos on land. But the alligators attack in the water. Both lions and alligators live in Africa, just like hippos. The hippo does kill other animals, but not to eat them. They don't like to eat animals. They are very protective of their family and friends. So if one of the hippos from their herd is being attacked or is in trouble, the hippo will attack and kill the animal hurting their friend. But they won't eat the other animal (unless they are REALLY hungry).