I have four two-year old hens. Three of them are laying eggs and one hasn't laid and egg since April. She is a Rhode Island Red and used to lay brown eggs. After her winter moult (which was her first as an adult hen), she laid about 4 jumbo white eggs, and hasn't laid an egg since. The color change was interesting, but I'm really concerned about the "no egg" thing! Does anyone have any ideas as to what is going on? She is healthy, eats and drinks, and does all the normal chicken things - except lay eggs!