hehe... "flatulence" eggs? lol! I am not quite sure what to do with mine, maybe make a hole and blow out whatever is in there and keep it. its so tiny and cute lol. So far that has been the only one I have seen! I only have 3 ladies laying green eggs, and they have all been laying normally since.Howdy MESOFRUFFEH
As ChickenCanoe has advised, it is a wind egg and yes, there is another name for it
I agree that new layers and old hens can lay them but I have also had hens that do not fit into those categories lay them also.
The hens are still healthy and laid normal eggs afterwards. So, unless it continues, I would not be concerned. I have only had chickens for two and half years or so and have had two wind eggs in that time.
I have bantams and both of the below were photographed next to bantams eggs:
They did not have any yolk when cracked open and they are kinda cute!