von N&&N » 6. Jul 2010 08:30
If they are not as active as before, it's time for hibernation. There are exogenous and endogenous factors which cause hibernation. They will show you.
If you have the opportunity, put them into the fridge. Start with a highest possible temperature, then lower it every day.
Don't feed them, just keep the nest moist. They need to get time to thicken there cytoplasm and hemolymph.
Good luck,
N&&N