My chicks are 3 1/2 weeks and have been using the ecoglow since day 1. They are in a spare room with natural light and I keep a regular bulb lamp on early in the morning and maybe an hour or 2 after sunset. I still have the brooder on the lowest level, but do have it propped up evenly about an inch on wood blocks. They seem to be fine I made the switch after the first week. They go under the brooder all night as soon as lights are out until I turn lights on in the AM. They use it occasionally durng the day but not very much. Last night I noticed one chick ( possbily lowest in pecking order that I can tell) wasnt sleeping under the brooder all night, rather she was on top, and she was there all night. Should I be concerned? I dont know if it was her choice, or if there wasnt enough room? What has your experience been. This is the ecoglow 20 and I ahve 5 chicks.