Just get two chao right next to each other and pet 1 and the other will be considered as being pet.(this works with as many chao as you want,but it would be harder with more chao because they will move around and walk away)

glitch-eating invisible fruit

when chao are hungry,they will go grab a fruit and eat it.pick up the fruit that they're about to eat and walk far away and set it down.they will follow you.then when they pick up the fruit,you pick it up at the same time as them and it will be eating an invisible fruit(they will not gain stamina,but it is funny to see them eating nothing)