Before I had to get rid of my snakes I would actually use a heat lamp clamped to a crate, with a bowl at the bottom of the crate holding the f/t feeders. Since I'm usually cramped on space the crate would be balanced on the corner of their cages. It only took about forty minutes to thaw and warm the feeders, and it had an added bonus of getting my snakes out of their hides and searching for the food. I didn't realize it until later, but I thawed rats and mice in the same bowl and ended up converting my ball python (who had only had mice from PetCo before me) right over to rats with no issues. I've always wondered if he was just not a picky eater, or if mixing the rat and mouse scents allowed him to convert to rats so easily. I've read a few posts on this site mentioning ball pythons who love eating mice and refuse rats.