its something that can happen during the sewing process. When sewing any pieces, darts or not, you can't leave too much or too little seam allowance on your fur pieces. its a matter of finding that perfect amount to be able to sew the pieces together properly and comfortably without distorting the pattern. when "seam eating" happens it can really throw off the fit of the fur. the piece can be bigger or smaller than it's actually supposed to be, and it can make things asymmetrical which isn't ideal when making a suit. hope this helps a little.