My son's rosy boa is quite small.. maybe a little over 2 feet long, and has a very very tiny head. (He is the snake pictured in my avatar.) Moving him up from hoppers to small mice when we first got him made me nervous, however, he has since been moved up to the largest mice the pet store sells with no problems. It takes him a little over a minute to get one down, and there is no lump showing after. He also acts hungry again after just three of four days. I'm considering trying rat pups with him. The pet store has offered to place an order for me when they put in there regular order (they don't regularly keep rat pups in stock). I am wondering what other snake owners (rosy or otherwise) think about this. I know the standard for feeding (1 1/2 times the widest part of the snake, large mice are less than that size), and that I shouldn't consider his head size when picking feeders, but his head is just so darned small it makes me nervous.. My rosy is almost twice his size, so I've never had any concerns with feeding her. (I am keeping her on large mice because she is old and not metabolizing correctly anymore.. even at one large mouse every week she is gaining weight, and she refused her mouse this week anyway.) Here is his head next to a nickle.. Note the lack of any bulge.. this was taken minutes after he ate a large mouse. Do you think I should move him up? Sorry the pictures aren't very good.. they were taken with my phone, and he wouldn't stop moving..