I have a group of 4.5 week old chicks in a brooder in a spare room in my house; I unplugged the heat lamp yesterday since they're pretty well feathered out and should begin to adapt for the move outdoors in another few weeks but I guess I didn't realize how dark it is in that room without the heat lamp on. There's a window but it doesn't let a whole lot of sun in. So what should I do about lights? Should I just leave them as is, in the dark? Or should I turn on the lights in the room during the day and then switch them off again at night or something else? I've read about white light making them more aggressive so I'm unsure about keeping the overhead lights on during the day...turning them on when the heat lamp was still in would usually make them go crazy so I don't want to incite that for half the day. But leaving them in the dark doesn't seem like a good idea either. Any advice?