Well, the title says it all really. But here's some addition info...
I have 8 birds total: 4 Buff Orpingtons, 2 "Green Queens" and 2 Barred Rocks.
Both of the Barred Rocks, 1 of the Green Queens and 2 of the Buffs are very clearly hens, however 2 of the Buffs and 1 of the Greens Queens have...