I recently picked up a pair of ferrets who get along incredibly well.  One is about 5 months old, and the other about 2.5.  They play extremely well, but while the little one is trying to sleep, the bigger one keeps trying to play and harassing him.  

I always feel bad because you can tell he just wants to sleep and isn't having fun.  Is there anything I can do, or is this normal? Sometimes he will even grab him and pull him out of the sleep sack or hammock because he wants to play.