Curiosity can also start pecking. When you change over to larger feeders and waterers it is helpful to leave the smaller equipment in the pen for a few days to help during the change. Also, allow 1 nest for every 5 hens. Vent pecking by layers is also a common problem. Once pecking starts it can quickly develop into a vicious habit.
Most cannibalism occurs during father growth in young fowl.
Birds with slow feathering have immature tender feathers exposed for longer periods of time leaving them open to damage from pecking. Don't raise slow feathering birds with other fowl. This will keep the birds busy and allow them to peck greens, ground and insects instead of other birds. Give the birds a large handful of fresh greens like clover grass or weeds, each day. This increases the fiber in the birds diet.