Kyo is sniffing his litter box, digging,and then napping in his cube. I've checked the litter box 3 times in the past two hours and there's nothing. He has eaten and drank some water. But he hasn't used his box. My aunt who is giving the litter of kittens away and gave me Kyo says that he is litter trained. Is he maybe not comfortable enough yet with the house to use his box?