Separating them really won't help. I'm going thru the SAME problem myself. I have SEVEN female tiels and this year I've gotten a bumper crop of fake eggs! Between 3 hens, I think I lost count at around 20 eggs!!! I have read up on it and about the only thing I've come up with is this: If your one that covers there cage at night, try feeding them ealier and putting them to bed early! The longer they are in darkness the better. This tricks them into thinking the days are getting shorter and winter is coming on. It hasn't stopped one hen I have but I've noticed it's slowed them down. I count myself VERY lucky that we've had no egg binding problems with as many as we've had.