My Reply : You can't know for sure if an egg is fertilised without breaking it open (or trying to hatch it). There can be several factors such as quality of food, quality of parents, weather etc, but generally, if you have a rooster who is doing his job and the rooster and hens are in good health it is fair to assume that at least 75% would be successfully fertilised. To spot check an egg crack it into a bowl and look at the yolk - there should be a small white mark somewhere on the yolk. When fertilised the small white mark becomes larger and more round and shows yellow in the middle so an egg that has been fertilised has a white mark on the yolk that looks a bit like a doughnut - in an unfertilised egg the white mark will be just a blob.

Susan : This is Kalu. He lived to be about nine years old. He was so polite and good to both people and his hens. My chickens were always loose as I live on a small island and we have no predators except the bald eagle and they don't seem to want to venture to the center of the island where I live. When I would go out with scraps and throw the food down, Kalu would call the girls over and show them where to find the scraps in the grass by tipping his head and looking at the morsel. He would repeat this until they found it. I used to call him "The Negotiator" as he would come to my front door and find me in the room and catch my eye. That meant, "more food please, and now? please". He died one November day. I had been in the chicken coop feeding and he came up and looked at me. It was odd and I looked at him and asked him, "What's the matter, old man?" I found him the next day. He was really something.