Giving your Chao lots of animals and Chaos Drives is good for making your Chao healthy. You can also give your Chao fruit from the Black Market. If you take your Chao to the Chao Doctor he will tell you what fruit your Chao likes (as well as many other things).Chao love to do activities like playing instruments and drawing, so you should take your Chao to the Chao Kindergarten. Buy seeds to grow trees and try to win all the Chao in the garden a watering can so they can water the tree to make it live longer. In game, under "Extras" there is a tutorial for Chao, which covers the very basics. The Principal can also help you understand things.

Chao eat fruits and nuts. The Nuts growing on the three trees in each garden are the basic food, they raise stamina like all fruit and nuts do. But verity is also important, so this is where the Black Market comes in handy. Round Fruit, Square Fruit, Triangle Fruit, their purpose is to give that needed verity. Chao only like certain ones, though, so taking your Chao to the Chao Doctor is a good idea to do first, so you can find out which they like. Dark Fruit and Hero Fruit are used to help make your Chao that alignment, and Heart Fruit is used to make the Chao breed outside of Breeding Season. However, Heart Fruit also lowers the amount of time your Chao lives, so make sure they're happy or they might die. Chao Fruit, which some say is like the neutral version of the Dark or Hero Fruit, is used to raise a Chao's stats in more then just stamina. Chao usually don't like this fruit much, after all, most people don't like eating spinach, right?