I just made a post about this. I have 3 laying EE , and today I put one of my silkie rooster in with the hens because he was being mean to the other rooster. This afternoon, I collected the eggs and 2 of the hens each laid 2 eggs! Could the rooster been the cause of this? Maybe inducing ovulation?
It can happen now and then. Quite awhile back I got a huge egg from one of my birds. It was an egg inside an egg and both eggs were double yolks. It weighed 185 grams/6.5 ounces. A normal large egg is around 60 grams/2.1 ounces.