We recently lost one of our older girls which left her sister all alone. So we decided to get two new pullets, unfortunately three days in one of them died (or got killed), it could be that something got into the new coop. but we are not sure. So now we have our older girl and this new pullet. Will it be a problem to introduce them together? we've been told it would be best to introduce 2-3 new birds with our older girl, instead of just one bird. but we are a bit stuck on what is best. has anyone introduced just single birds to each other successfully ?