Chicken Coop Door Too Big

Im not new to keeping chickens over the last 20 years of having them. But I found something new that I was doing wrong. My entrance to the coop was causing problems with my flock dynamics! Im not sure if this is just my flock or a general chicken thing. But my coop was originally for goats not chickens so iv just been leaving open the big 3 foot by 4 foot door for them to go in and out of for about 2 years now. I had gotten quite a few new chickens at that time as well. But ever since my hens had all there back feathers missing and half the eggs would be eaten. I have 2 roosters for 40 hens, rotate pasture twice a week with electric poultry netting and have clean nest boxes raised above the ground so they cant see the eggs unless they jump up. The coop is about 12 foot by 12 foot as its mostly just meant for at night. But they wernt using it just at night they were ALWAYS in the coop. All 40 in that little tiny space. No wonder Im having problems. So I try to fix it. There pasture is filled with fruit trees so lots of shade. I keep the feeders and waters on separate sides on the pasture to encourage venturing out. There's areas for dust bathing and roost outside of the coop. I tried mowing the pasture before moving them to it and letting it grow long. Changed there food, tried treat blocks and running water. Brought a few into the vet to see if there was anything wrong and got her input on what I could do. But they wouldn't stay out for the life of me. Until about a month ago one of the hinges finally broke on the big door. So I started just kind of propping it open so there's only like a 1 foot gap instead of a grand entrance cause its harvest season and I dont have the energy to fix it right now.

They FINALLY started leaving the coop!

They hang out side all day! even the neighbors noticed the difference! I have no idea how much money I have dumped into trying to fix this problem when all it needed was a new door but Im so pleased to have happy chickens again! Is this a common problem? Has anyone else noticed this or do I just have odd chickens?  

That is wacky, who could of guessed the entrance had such importance!

I wonder if it is a comfort factor for them, like a sort of worry about predators if they were near such a big opening?

Thank you for sharing in any case.

I think your on point with them being more comfortable with the lack of a big hole in the wall. I wouldn't want half of one of my house open to the world knowing there's things that want to eat me either.

Maybe it was too much sun light? Or maybe the smaller door make them feel warm and cozy

And safe from predators...

Chickens can be odd creatures, you never know what is in their heads. I'm glad you finally found a solution.
I have been changing things in my coop, and chicken yard,  Everything new or different is not to be trusted. So far with time they do adjust.

Yes, this is definitely a common thing — your chickens are not odd at all.

The rule of thumb for a chicken pop hole is something like 10x10 or 12x12 inches: big enough for a hen to walk through comfortably, and no bigger. Your 3x4 foot doorway was a barn door from their perspective. Hens are prey animals, so a huge bright opening makes the coop feel exposed rather than like a safe roosting spot. With the smaller gap, the coop stays darker and den-like, and that is exactly what they want — darkness is also why they prefer dark, private nest boxes for laying.

A smaller door has some practical wins too: fewer drafts at roost height in winter, and a much smaller opening for predators to exploit. Sounds like your fix already proved the point, but you are not alone — plenty of people run into this with converted sheds and barns.