So I have two cats that I've had now for 4 days. One is very shy and the other more out-going. How do I know if they're both eating? There is food gone, there is waste in the litter box, but how do I know if the shy one is eating anything? He hides under the bed or cowers in a hut when I come into their room. Should I just asuume that a cat will naturally feed itself? He is moving around because he is in a different place occasionally.