Rhinos sometimes fight with each other. Black rhinos use the bigger of the two horns on their noses as weapons in a fight.
Their horns, made of a substance similar to that of human fingernails, sometimes break off, but they regenerate, or grow back. Female rhinos also use their horns to protect their babies from predators such as lions, crocodiles, and hyenas.
In spite of their fierce reputation, black rhinos do have a softer side. The females are very attentive mothers. They look after their young for years, protecting them from enemies and teaching them how to survive independently. Young rhinos usually stay with their mothers until a sibling is born. By then they're generally over two years old, almost adult size, and ready to live on their own.
Humans are the only real threat to adult black rhinos. In several Asian cultures, people believe that a rhino horn provides powerful medicine for a variety of ailments. Other people, who live mainly in northern Africa, use rhino horns to make the handles for special daggers. Since rhino horns fetch high prices, many poachers are willing to break the law and kill these endangered animals.
There are five different species of rhinoceros: black, white, Javan, great Indian, and Sumatran.