Don't cut their beaks!!! I fixed my egg eating -- dont' listen to people who say it's not possible.
Chickens eat eggs because they need the minerals and/or because they crack in the nest. So...
1. Make sure they're eating lots of protein and trace chemicals. Add black oil sunflower seed to their diet -- give it to them as a treat once a day. I heard that feather eating is also caused by a lack of protein/trace minerals that are in sunflower seeds, so if your chickens are also plucking feathers, this might help that, too.
2. Put a piece of carpet sample in the bottom of the next. This will help keep eggs from cracking even if the shells are thin. Shells get thin naturally in winter, which is when egg eating seems to happen the most. I give mine oyster shell, too, but it doesn't always keep the shells from getting thin.
My chickens are two years old and will occasionally eat an egg, but only if it breaks -- and it usually breaks because some dumb hen lays it on top of a two by four or something. My first winter with them I freaked because I thought they were going to keep eating half the eggs and I'd have to cull them. But it's not longer a serious problem.
