We've only had chickens for a little over a year, and still don't know very much about illnesses so any help would be really appreciated. We added three new chickens to our flock a couple of weeks ago, same breed and size, foolishly thinking they might get along (we were told they would be fine if we added the new chickens at night-that didn't work). We separated them again, but now our original hens are sneezing and their laying has gone from seven a day to one every other day. Is there any way to tell the difference between a harmless virus and the flu? Can viruses be transmitted through the eggs if not properly cooked or through chicken poo (which is pretty common in the yard)? Are the eggs safe to eat, or should we get rid of them until we know what's wrong with the hens?