After 21 weeks or more of anxiously waiting to pick your first fresh eggs from your laying hens, to your utter dismay and disappointment you discovered that your chickens are breaking and eating their eggs.

This can be a very disappointing and painful experience. This problem of egg eating and breaking is not uncommon and is very possible to prevent and stop it completely.

If your chicken are eating, drinking and breaking their eggs, you need to discourage them, and break this habit immediately. The longer you wait to correct this habit, the harder it will take to cure them of this terrible habit.

source: http://bnetlens.com.ng/egg-eating-why-your-chicken-are-eating-their-eggs-and-how-to-prevent-it/