I never put rodents in my human food fridge. If you are referring to using a fridge that is exclusively for reptile food then I think that is fine and acceptable. Personally, I use a couple of other methods to defrost rodents. For the small and medium rats I sometimes place them on paper towels to thaw out straight out of the freezer for several hours. Then I warm soak them in moderately warm water for about 1 hour in zip lock bags. Just prior to offering I blast them with the blow dryer. The hatchlings eat rat pups and they get set out at room temps for about 2 hours then placed in zip lock bags into warm water. The rat pups are then offered and usually snatched up without hesitation. If a hatchling seems interested in a rat pup but doesn't strike and wrap it then I hit it with the blow dryer and reoffer. Rat pups are more easily warmed bc they are a lot smaller and less dense.