I have questions about cats?

They're probably not on solids yet, give them a few more weeks or try to feed them cat biscuits mushed up with a little kitten milk. (You can buy both at TESCOs or most supermarkets). Try to get them in the house and tell your little cousin that they bite and scratch. If that doesn't work give him one hell of a telling off when he trys to be too rough with them.