I started to feed mine f/t rats recently seeing as how they are huge and this takes the chance of him getting hurt. i let mine thaw out through the day on top of the tank. mine take a good 8 hours to thaw cause they are jumbo rats...urs shouldn't take near as long. Pre-senting is where u introduce the mouse or rat into the room so the sent can be carried so the snake can start to sence and smell it. Therefor getting the snake worked up and letting him be awarethat there is food on the way. Hope some of this helps!