<B>How old is your ball?</B> Many subadults and adults begin fasting around this time and most likely will not take any meals until spring. Babies however usually eat through their first year, though it isn't unheard of for them to go fast as well.
<B>What is your setup like?</B> He should have several hiding spots to feel secure in (unless he's in a rack system, I have found they don't usually need hides in these setups). The larger the enclosure the more hiding spots you will need. Are your temps ok? Do you have a gradient of 78/80 - 88/95?
<B>How long has he been allowed to acclimate?</B> Have you given your snake at least *one* week to settle in without offering him food or handling him? Also, I wouldn't recommend handling him until he's feeding regularily for you. Balls don't tolerate excessive handling and the second they get stressed they tell you! They just refuse to feed. Is he in a high traffic area of the house? Is it possible a cat or dog could be bothering him? Try again in another week.
<B>Did you leave the prey item in his cage overnight with him?</B> Sometimes balls can be very shy and they will take the prey item if left overnight in their cage (make sure it is dark). If it isn't eaten by the next day then you should throw it out. Bacteria triples in the dead rodent every 15 minutes
Though some animals seem to prefer a stinky decomposing animal to a fresh one...
Anyhoo, hope this helps you figure out a little more. Take care