why dont you feed your ball in a seperate enclosure?
my ball is in a tank with a coconut fiber and moss substrate to keep the humidity up
but every tuesday at 2:30PM i take her out and put her in a empty Pabst Blue Ribbon case lined with paper towels...I drop the mosue in,she strikes...she eats, I put her back in cage,no worries
it's a good habit to have,it helps them associate that your hand is not food,should you reach into the tank