Dew, how hot do you have it in there? Are they concerned you’re trying to cook them without cleaning them first? Would you be uncomfortable in there wearing a heavy down coat?
Are the heat lamps the only thing that has changed? If they are throwing a lot of light in the area, maybe they can’t tell it’s bedtime.
Chickens don’t like change. Maybe they just don’t trust those new heat lamps. You could be scaring them.
How are they acting at bedtime? Are they still out foraging or are they huddling or trying to roost somewhere?
It’s possible something scared them in the coop and they just don’t want to go back in there. I’ve heard of that happening but I’ve never seen it myself. I’ve never had them afraid to go back in.
I’m trying to remember if you and Monty got some new pullets. Are these maybe fairly young ones you are integrating with your older hens? If that is the case, the older ones are probably being such bullies and brutes the young ones are afraid to go in with them. They think it’s safer outside.
If it’s not pullets afraid of older hens, get rid of the heat lamps. They really don’t need them.
