I always equate ball pythons to cats, and boas to dogs;
Balls, like cats, do what they want, when they want, how they want, regardless of what you want.
Boas are like dogs...throw something in the cage and they don't mess around.
Anyways, I would place something relatively harmless in the cage, that is live, and let them warm up to it over a few days, in peace and quiet.
BrandonsBalls
(no offense to cat lovers, but everyone knows they are the fickle, independent sort.)