My red cochin has hatched 2/6 eggs. One chick is healthy, but one either died after hatching of natural causes, or didn't get covered well enough by mom and froze - was in the 30s last night. My buff hen has hatched 3/6 and one more egg is almost zipped all the way around. She keeps getting off the nest with the 3 chicks and leaving the eggs though, so I am starting to get a little concerned about her behavior since technically, tonight at 11:45 pm is the 21 day mark. Is it very bad if she is getting off the eggs for several minutes at a time when they are in the middle of hatching? It is 45 degrees out right now...