Hi mate could be a silly question but are you defrosting the rat and how are you defrosting it if you are she is probably a bit stressed from the move but there is nothing to worry about at all at the moment rat pups are definitely too small for a 2 1/2 yer old ball python unless you have got your wires crossed with the name of the rats age if you post pics up of your ball python and it's food when you get home from work people will tell you more confidently if it's the right meal your feeding her. By saying defrosting I mean thawed for the correct terminology