Food Size Question

[Kate]

Ok, kind of a newbie question for you all. I've had my bp for about 9 months now and she doesn't seem to be growing as fast as other peoples snakes. I'm not sure if this is something I'm doing or if she's just a slow grower. She's almost 2 feet long and about as big around as a toonie. I usually feed her one adult mouse once every 10 days (give or take a day or two). She has not gone off food while with me and has never refused a meal. I'm basically wondering if this meal is too small for her or too infrequent. I don't want to over feed her but I don't want to under feed her either and since she's my first bp I don't really have any experience to go by. She's never refused a meal and she's never gone off feeding. Everyone says tailor the food size to the snake size but can anyone be a bit more specific than that? Should her food be smaller, larger or the same size around as her? What about length? The small/juvenile rats they have where I get my mice are quite a bit longer than the mice and they look big because of that but really aren't much bigger around. I think they are a bit bigger around than she is but how big is too big? Would she just not eat it if it was too big or would she hurt herself trying to get it down? Also, should I try switching her to rats now or are the mice ok? Thanks for reading my long rambling post and for any help you all can give!