They won't go in the coop at night-help!

I have 4 pullets (well hopefully), 2 Silkies, a Welsummer, and a Barred Rock that are about 11 weeks old. They have been outside for about 2 weeks now. I have a small coop with 4 nests and 2 sets of roosts, about 3- 3.5 feet tall, 6 feet wide, and 2.5 feet deep. It has a large completely enclosed run attached to it. There is a ramp since it sits up about 1.5 feet. There is food and water inside the coop. We haven't had a chance to put a door on it to shut them in yet.

My problem is that from the first night they were out, they sleep in a ball all curled up against the pen fence in the corner furthest away from the coop in the grass. I have been crawling into the run (which is about 3 feet high and covered with wire on top) and putting them into the coop every night for the 2 weeks they have been out. Once I put them, if it's dark enough out, they settle down and stay in till morning. But, they won't go in at night by themselves. They start congregating in that corner in the evening and stay there all night, even when it's raining! This is getting old very fast.

I thought the problem was my ramp, but I went out one day and put grapes on the ramp and up into the coop, and they ate the grapes on the ramp but jumped off the ramp as soon as they got to the top. I saw them out there playing on the ramp, going up and down it, the past few days, but not going inside the coop. So, last night, I put their entire food container in the coop, so that in order to eat they have to go inside. Today, they were going in and out to eat. But, now (about 6 pm), they are settling down in their corner in the grass again.

Any ideas? Do they not like the coop maybe? It's big enough for 6 chickens, I'd say, and there's only 4. We intend to build a bigger one, but this has to do for now. I'm just frustrated with crawling in there to put them in every night!

 

Ok, I'll try that. It won't get too stuffy in there? There are a couple small ventilation slits in the sides. I guess I just feel bad leaving them in there so long cause they seem to love scratching and playing around outside.

 

Yes, they did have a red light while they were inside. I can't put a light out in the coop though cause there's no electricity out there. I'm gonna try to leave them in for a couple of days and see if that does the trick. If not, I have no idea what to do!