How small an opening can a BEI fit through?

[hfchristy]

We somehow ended up with three bantams (one of them rather runty) and 6 large ducks. I'd like to set up a space for the little ones to get away from the others if they need to, and possibly to set up some extra food for them in there.
Does anyone know what would be a good size opening to let a couple of Black East Indies and similar sized bantam in but not ducks around the size of, say, Welsh Harlequins?

 

[svh]

I'm not sure on the size of the birds you mentioned, but I used cinder blocks, on their side, like little tunnels, for my littles to escape the bigs in an integration earlier this fall.

The babies learned quickly that they could zip right through the tunnel, and the hens big fat butts would get stuck, and have to back out !!!

 

[CayugaMama]

Cinder block size would be perfect! My BEI can fit through about a 4-5" hole.

 

[svh]

Cinder block size would be perfect! My BEI can fit through about a 4-5" hole.

Plus, you can turn them 90 degrees, so the tunnels go up and down, and deny access. I cut holes just smaller than the blocks in the fencing, and placed them up against it for little escape routes in and out of the brooder.

 

[hfchristy]

Apparently our big ducks can squeeze through a 4x6 inch hole! At least, one of the girls managed it. She had a tough time figuring out how to get back out, though!
I guess we'll wait and see if the boys can get through since that's the big reason we wanted to separate them.