Horses usually stay with their parents until they're about 2 years old. When they are about 1 year old, they become a yearling. The picture above is a foal with its mother. The foal isn't a yearling, because it isn't that big. Some foals are taken from their mothers when they're weaned, (or don't nurse anymore.) Some foals are kept with their mothers till they are 3, and then they must be trained and sold to someone.