smaller reallly isn't going to matter in this situation. The important thing is to get food into the snake and have it feeding regularly. Larger mice I am able to find locally in San Diego, not sure where you are located, but you could also try F/T.... a nicely warmed up F/T adult mouse or even rat pup might be less of a scare to your snake. Also if it refuses it you could always freeze it for one more try.