Yes, thats normal although they shouldent do that. Every once and awhile my chickens will crack open a egg and eat them since they taste so good. To stop them from doing that you can colect eggs very oftain or get a closing nesting box door which will open and close for chickens only who want to lay a egg and not eat the eggs.
The cause of egg eating is if an egg is left in a nesting box to long a chicken may become interested in its taste and crack it open to taste it. And since eggs taste so good to chickens raw they will keep eating them unless you colect eggs Very oftain. Many times a day would be good if you can.
