There are a couple ways to keep chickens entertained.
You could hang a whole cabbage by a string for them to peck at, or cut any melon or pumpkin in half (which usually takes them a while considering the fact that they even eat the rind!), and keep in mind that chickens can practically eat...
Rhode Island Reds are known for being slightly too aggressive.
Some possible causes are:
1) Protein (as mentioned above)
2) they are bored
3) they don't have enough space
Those are the 3 main causes for feather pecking and possible egg eating. They could also be eating eggss because of the...