my gliders seems to be changing their sleeping routine lately. they used to wake up around 10-ish and be active most of the night but asleep by early morning - maybe 4 or 5 a.m. But lately they have been staying asleep until after 1 a.m. and staying up until 7 or 8 a.m. No other changes to their food, habitat, or routine. Any idea why this would be?

thanks!