i toss all the rats i need for feeding in an extra tub in my rack, i let them sit in there with the small rats over the heat tape and anything smaller not on the heat tape for about 4 hours or whenever they're fully thawed and not cold to the touch, then i give them a quick blast with the hair dryer and they're ready to go.

what i like about this method is that the hair dryer acts as a pre scenting mechanism and everyone gets excited about their food and is waiting for me to drop their rats in.