Pick it up and rock it , after that, pet it a lot (a lot!)

If you put them in the water for a long period of time the Chao should eventually not cry. Chao cry if the fruit has been taken away from them (unless they drop them).

You've probably spoiled them with love, so they're cry babies and depends on you too much, I'm not an expert but you may want to take them to the doctor to check on them i.e their stats so you can see their personalities.

Chao often cry because they want food or they are tired a chao with the crybabby personality will cry more often when it wants something
chao may also cry if you accidentally take their food away

They are not being fed, angry (pet it) or want something

They're just spoiled. Face it, you screwed up.

If theyre crying, it means theyre hungry, if theyre like.. weeping? it means you have to pet them for a while

For Matt, chao sometimes mope, but I don't know why. My chao do that, too; even the chao that love me a LOT! (and some that are neutral with me do that, so it's not from spoiling them). For Jonas, you've overfed him. He's sad because his belly hurts from overeating. For Lilly, a chao only lays down and cries when they're hungry. You've probably forgot to feed Lilly for a couple days. You were too busy feeding Jonas.

you spoiled your Chao, this means you pet and rock them too much. Chao need space so let them be for a while and just give them chaos drive otherwise they stay angry and sad

Oh yeah also you dont have to feed your chaos they can eat on there own.