6-16. 啄毛是指雞隻去啄吃另一隻雞的羽毛。啄毛最先見到的位置是在背部及尾巴基部，被啄光的雞隻會較容易損傷和受感染。啄毛發生與雞隻太無聊及階級行為有關。 Feather pecking is when a chicken pulls out and eats another chicken’s feathers. Feather pecking is first visible at the bottom of the back, at the base of the tail. A bare chicken is more susceptible to injury and infections. Feather pecking has nothing to do with aggressive or rank order behaviour.
籠飼與放養的雞隻：啄毛常發生在所有的飼養系統。在平飼系統會比籠飼出現更大之問題，大群的平飼雞隻發生啄毛時，會造成更多的受傷雞隻。 Caged versus uncaged chickens: Feather pecking occurs in all husbandry systems. It is a bigger problem with uncaged chickens than with caged birds. Uncaged feather peckers in a large group can create more victims.