If they are going to a pen/coop by themselves, then they can go out now with their heat source. Or you can wait till they are six weeks or fully feathered and then put them out without the heat. Generally most wait till the young ones are twelve weeks before putting them with the rest of the flock.
So my question is how much longer till i can put these guys in the coop? & of i do will i need to make sure the red lamp is still there for them? (The three littlest ones im not asking about)
I just want to make sure I do this correctly and when the best age would be. I will let them see my other flock for a couple weeks prior to letting them all be in together.