I've been dealing with brumation for 11 years and every dragon is different. Cierra, Nathaniel and Castiel are the first dragons that I've ever owned that slept in the summer, Cierra sleeps for 6 mo, normally not up until Feb. Castiel and Nathaniel sleep until Nov/Dec. I think Imp is going to want to sleep, too, but he's not allowed to do a full brumation until he gains more weight, so I'll keep his lights on so he's up in the am and continue to feed him daily. Gabriel is the same, even though I'll let them both sleep the occasional day but still with lights on. The other three have their lights off for the time they sleep. I have always hated that they brumate or slow down in the winter time, it's so hard on them. They can lose alot of weight, if they don't get into deep sleep where a hormone is produced to slow down their breathing and heart rate. In the wild they brumate because of lack of bugs and greens, keeps them alive during the winter. In captivity, they don't need to do this, but are hardwired for it. I've had a few with issues after they woke up; pulled muscle in a back leg, lack of energy when they wake up, lack of appetite, too. That's when I pull out the mix. So we'll see how Darwin handles this winter.