Thank you for the replies and for not dancing around the issue. Someone pointed out how weird it is that this happened when I've had him for a year, I'm pretty sure the reason this happened now is because I changed the type of container that I thaw the food in. The shapes of the containers effected the position and level of submersion of the rat. The fix is pretty simple, I either need to go back to using the old type of containers, or mess around with the new ones until I find the amount of time it takes to thaw. However, that isn't an excuse and my actions were lazy and irresponsible, I'm very grateful that he knew to spit it out. Again, thank you for the responses, this experience was a big wake up call and I plan on reviewing my husbandry in general to make sure nothing like this happens again.