Tiny dark speck in showing up egg yolks

[Blue Ridge Hillbilly]

I am have a number of eggs showing up with a tiny dark speck attached to the exterior of the egg yolk. These are barred rock pullets that have just started laying. I am feeding layer crumbles, whole corn, scratch and some oyster shells in a separate feeder. They get plenty of fresh water. I have 24 pullets and three roosters. The speck is showing up in about 1 out of 5 eggs. Any thoughts?

 

[Illia]

Absolutely nothing wrong with them, just little bits from inside the hen that fell off and entered the yolk. It happens. Nothing dangerous or inedible.