We got 2 Easter Eggers and 2 Wellsummer on April 25th. We don’t know how old they were at the time... I suspect anywhere from 7-12 days but their feathers seem more mature... they have been outside 10 daylight hours per day in their run in temps between 75-90 for about 6 days now and start chirping just when it’s starting to get dark so I bring them in . They have not had heat lamp on in their brooder for 8 nights now (house is kept at 77). It’s about 64 outside over night these next few nights. Any thoughts on how old they appear to be and how soon they can stay in their coop overnight?