My favorite/ what I've found to be easiest and best for the kits, I bring the kits, nestbox and all into the house somewhere warm and somewhere I have a towel or some warn fabric to put them in and I pull them out one at a time and check them all over, make sure there are none dead as well. Its also fun using the how to sex day old kits photo and attempting to guess sex's. Although I doubt I'm ever right at first lol