He's still the new kid just give him some time to adjust. As long as he is eatting he should be fine. I always explain this period to customers as "If I shoved you in a black plastic bag with just enough room for you to turn around in and then shipped you 1/2 way around the world only to drop you off in a place where you didn't know anyone and then tossed food you had never seen before at you, would you be ok with that?"