that is clearly not a small amount of bleeding. I have always had roosters and have only seen this on eggs I obviously missed from the day before.Not necessarily. I've had one or two of these without a rooster around. 0% chance of fertilization. It can also be caused by small amounts of bleeding when the egg is forming, usually from a ruptured capillary. It can also be a sign of reproductive problems starting in a production breed hen, especially if she is a bit older. It is disturbing, but harmless for consumption. I would not blame someone if they tossed said egg though.