One of my faithful customers sent me this picture this morning as she boiled several eggs. These eggs were laid last week. It is very strange that all but one had this strange dark orange ring in the yolk. Any suggestions of what this could be? My hens are not sick that I'm aware. The only odd thing I've fed them a couple plus weeks ago was boiled crawfish. Whole crawfish that were leftover from a party. Could this have caused the ring? Any help is appreciated!