Ok good to know, that at least the aren’t particularly susceptible. The reason we want more is probably for more egg production (we are only getting only like 5 eggs a week) along with variety of egg colour and we just love chickens. We have the space and two more chickens would complete the set. There was a time when we had six and I just really liked that, it just seems little with four. Obviously if there is just too much risk involved in getting more birds, we won’t do it.