Each animal has its own set of behaviors that you can control by tapping on it. For example, the cow will start to moo when you tap on it, and the chicken will start to lay eggs.
You can also breed animals by putting two of them together. The two animals will start to make a baby, and after a few seconds, a new block will be added to the world.
The baby animal will have the same behaviors as its parents. For example, if you breed a chicken and a cow, the baby will be a cow.
You can also tame animals by feeding them. Just tap on an animal with a food block in your hand, and the animal will start to follow you. To make a food block, just tap on the food you want to eat, then hold and drag it to your hand.