Eggbinding is a serious condition of being unable to lay eggs for either medical, nutritional or environmental reasons. Metabolic bone disease caused by inadequate calcium or UVB can cause it, as can just poor nutrition in general. Lack of a laying bin, or an inappropriate laying bin can also cause eggbinding. Some females are more prone to it than others for some reason, but having been bred or not has nothing to do with it. It is fatal if not treated, and unfortunately is a common problem.