Aww what a cute little punkin' ! I bet its just that he is nervous from being in a new place and away from mommy and siblings. He will adjust well I'm sure. Both of mine acted like that the first couple of days. Then they saw all the love and attention and safety we were able to provide them and have been on non-stop a roll ever since!
Keep offering him food and water and keep taking him outside or to his paper whichever your doing. With our 2 I took them around to each room of the house they were allowed in and put them down so they could explore. I did this so they would not have the fear of getting lost. Worked wonders!
Might want to grab yourself some nutracal to be on the safe side, though I only used karo for Kammie and it seemed to work fine.
Just give him lots of luvin's and he will relax I'm sure!
Best of luck!
Keep posting pics of that little cutie pie!
