Is My Cat Catman Sick?

My cat mate, Catman, have been living in my home for one and a half month. I gave him the same food as which his former host gave, and I also play with him all the time. He is supposed to be happy but sometimes it doesn't look very well. I don't know if he start to miss his old host. And I am very afraid that he may get sick. So I start to read some books about cat care.

Cats are susceptible to a number of different basic diseases. There are a number of different diseases that cats can suffer from, such as skin diseases, ear diseases, nose diseases, mouth diseases, even mental diseases. Take care of a cat is not only just feeding him well, but we also need to pay attention on his living conditions. For example, regularly brushing your will keep them clean, and reduce the hair which he will licked off and swallow. And this is the most efficient way to avoid the hairball problems for you cat, and it is also the best solution to keep your house clean without shed cat hair.

No matter how much I know, I still can not find the reason why my cat looks like very unhappy sometimes. And I feel very much ashamed because I promised my friend I would take care of him well at that time. To find out the treatment, I have to ask for some advice from my vet friend. To my surprised, the reason why my cat, Catman, looks like that is just because he is tired and he wants to have a sleep. -_-!