All but pigs and hippos 'chew the cud', like cows. This means they chew food again after first partially digesting it in a special stomach. Deer are browsers, feeding mainly on leaves. Like cows, they are ruminants - that is, they chew the cud. Buffaloes belong to a large family of artiodactyls called bovids, which includes cows and antelopes.
Male bovids have big horns which they sometimes use to defend themselves.
The giant pandas of China have a special pad on their front paws, called a sixth finger, for holding bamboo stems. The bamboo shoots they eat are not very nutritious, so pandas have to spend 10-12 hours a day feeding. But ecologists now feel that the effects of human activity may be driving many more to extinction. They are convinced that a few species of mammal are dying out each year already. But what they fear more is that as the plants on which they are dependent disappear, so more and more species of mammals will face extinction in the near future.