Hello aguu, I was thinking along the same lines as catwoman when I read your post. Maybe your new kitty misses his companions. I know when my family's kitty Winston died when I was in high school, my other family's cat, Socks just wandered all over the house crying and meowing trying to find Winston. This lasted for several weeks. I think animals go through a grief period when they lose a "sibling". He probably doesn't know what happened, and maybe is searching for his companion?? Maybe you could think about adopting a homeless kitty from a local shelter?? There's always room for one more kitty! LOL In any case, what catwoman suggested might be worth a try. Could you go and visit his kitty sibling, to see if that is what's causing it? Play with him and cuddle him a little more...he may just be missing his playmate. I'm happy to hear that he's fine otherwise! *hugs* from me and my babies! Keep us posted!