I like to thaw feeders over a longer period of time to avoid the skin breakdown of the belly area. The breaking of the belly skin can happen from heating the feeder too fast, or multiple freezing and thawing.

If you believe it to come from the rapid heating of the prey item, take it slow next time, Medusa can wait the extra hour or so unless you're in a rush then you can slow thaw the item at room temp or in your fridge.

It could also be your supplier. If you get your feeders from the pet store, who knows how many times the prey item was frozen and refrozen. It's always a good idea to get quality food, even for your snakes.

:-)