same thing happened to me. I've seen fertile and non fertile eggs and am VERY CLEAR on the differences. Yet, many of my eggs were showing an unmistakable bullseye and there isn't a roo for miles. It's impossible for a roo to have gotten anywhere near my birds. I live in town where roosters are illegal and they spend much of their time in a fully enclosed run (including top to keep hawks out). Yet I saw bullseyes. I even posted them to ask if i was seeing things. Several experts on here agreed. Bullseyes.
Out of curiosity, I stuck them under a broody for 5 days. Zero developement, as I expected. Ijust wanted to goof off and expected nothing to happen. After that I stopped looking because it didn't matter anyway. For all I know they're still showing weird bullseyes.
So. How it possible? I don't have an explanation but I do know that it is totally possible for a non fertile egg to have a bullseye and fool even practiced chicken keepers.
