I currently have 6 bantams, 2 roosters and 4 hens; OE, silkies and dorkings. They are about 5 months old right now and I have ordered 15 chics that will arrive around 9.25. I am pretty sure that the bantams were vaccinated. We were told by a local vet that raises chickens not to vaccinate our chics. So we didn't. Is this going to be a problem? How will our banties react to the new hens? Should I do something special to prepare them? Thanks!