2 questions

First, do bps give any signs that they are hungry...are there any behaviours that would indicate they want to be fed more often? (I've been feeding my baby bp every 5 days...but last feed I switched to f/t and I think the frozen mice I got my hands on are a little smaller than the live ones I had been feeding him)

Second, how do I know when I should switch him to small rats? Other than eyeballing the size of the rat compared to his size..is there any particular time-frame that's good for switching?

Thanks!