I've had him for about 4 weeks now and so far he won't eat

It's my first ball python, so i make be doing something wrong im just not sure what???

I tried to feed him 1 week after i got him (he received no contact etc), but no such luck- i feed him f/t mice which i heated in the microwave until they were warm and then kind kind of "walked" them around him with a pair of tongs- today i tried to feed him again, but he wouldn't eat.

His tank is a stable temp of about 82 day time and 78 at night, with a heatpad on one side and hides on both. 20g long. Water bowl in between.

Am i doing something wrong? again, my first BP, i keep mostly fish so this is new to me

Should i try to feed him something different???

thanks
tim