I saw an ad on Craigslist from a guy that is selling 3 laying hens. He said they are 13 months old and he has raised them from chicks but he has several more and does not need that many eggs. Now that we have our coop complete I am so excited to get some eggs I don't want to wait until Sep. to see my first one. I thought of buying them from him but was wondering if they will kill my existing flock. I have 15 chicks and 6 guineas. What do you think?? Should I go for it?