Smallest door size for buff orpington?

[AnnaLease]

What is the smallest size of chicken door that I could have on my coop that buff orpintons could fit through?

 

[Pharm Girl]

I find it quite amazing what chickens can fit themselves into and I think it's because they look bigger than they really are with all those feathers. Especially large breeds like buffs. I have a small cat door that they happily squeeze themselves through. My EE is even bigger than my buff and she makes it too. Not sure if all chickens will do it, but mine will for the price of freedom!
That said, the opening needs to be close to the ground, not 6 inches high like you might make it for a cat...

 

[laseterlass]

LOL. I did not even think of that. I made the hatch opening a square foot. I hope they will got through it!

 

[Bearsfan]

I have had two WR's and a BO in the nest box at the same time, and I am using milk crates. They fit in places you wouldn't believe.

That being said, I would make darn sure that there are no rough edges or any place for the birds to get snagged going through the hole. They will definitely be rubbing the edges of it. You wouldn't want them to get their combs or feathers caught and ripped going through.