How do you measure for a leg band on grown Buff Orps? I have had two broody BO hens raise two hatches this past summer, one hatch is two months older than the other and I would like to band the birds to keep track of the hatch and generation, especially to visually note which two were my broodies so I don't lose track of them. I saw online some circular plastic bands that were kind of like those rings you slide keys onto, are there better types than others? Please help me keep track of my hens by pointing me in the right direction regarding leg banding, safely. Thanks.