Being able to refer to the common names of the outside parts of the chicken is helpful when describing a problem to someone long distance and to ensuring the health of your flock.
Eyes: Chickens have better vision than people, by several measures. Their ability to bring objects into sharp focus and to notice very small differences in color is better than human vision, even in newly hatched chicks. Chickens can even see ultraviolet light. (Unless you have super-human powers, you can’t.) In case you were wondering, the most common chicken eye color is reddish-brown.
A chicken’s upper and lower eyelids aren’t meant for blinking. Instead, chickens have a third eyelid for that — the thin, translucent nictitating membrane. When it’s not in use, the third eyelid is stowed in the corner of the eye nearest the beak. It acts like a windshield wiper, or sometimes, safety goggles.
A chicken reflexively pulls the third eyelid up over the eye whenever she needs to clear some eye gunk or avoid flying debris (or a kid’s curious finger). When a chicken is sleeping, the lower lid is pulled up to close the eye; the upper eyelid doesn’t move much.
Ears: A fringe of feathers surrounds the opening to a chicken’s ears. This opening leads to a canal that ends at the ear drum. Chickens’ sensitivity to sound and ability to hear low and high pitched sounds is similar to human hearing ability.
Skin: The skin of chickens is very thin and stretchy compared to yours. Chicken skin has no sweat glands. You can find skin glands on a chicken’s body in only two places:
The ear canal: The glands in chicken’s ear canals have the same function yours do: making ear wax, which provides a barrier to germs and water.
The base of the tail: The preen gland, also called the uropygial (say it: yur-o-pie-jee-el) gland or oil gland, is on the back of the chicken where the tail meets the body. It produces oily stuff that a chicken works into her plumage with her beak. She does this to make her feathers water resistant, but there may be other beauty secrets involving preen gland oil that she's not sharing.
Feathers: Chickens have between 7,500 and 9,000 feathers (someone counted them!), that are made of the protein keratin, the same stuff that beaks, horns, hooves, hair, and fingernails are made of.
Chickens shed old worn-out feathers and replace them with new ones in a normal, orderly process of molting. Molt is an annual event for most chickens, typically happening in the fall, although stress or changes in weather can trigger molting, too. Molt follows a regular pattern of feather loss over areas of the body, in this order: head, neck, breast, body, wings, and finally, tail.
Large wing feathers are dropped in a definite order, starting at the center of the wing and working out toward the wing tip and then, from the center of the wing toward the body. The process of molting can take as little as six weeks, or as long as six months, depending on the bird.
How a hen molts can give you a clue about her egg-laying prowess. Your best layers are the ones who quickly finish molting, and they often look terrible while it’s happening — they’re the raggedy hens with bald patches. The pretty girls who molt gradually and never have “bad plumage days” probably don’t produce many eggs.
Toes: Chickens have four or five toes, depending on the breed. Bony outgrowths on the insides of the legs, called spurs, appear in both males and females, although spurs are more well-developed on roosters.
Combs and wattles: The comb is a fleshy crest on top of a chicken’s head. Wattles are the pair of skin flaps hanging from a chicken’s throat. Both males and females have combs and wattles, which come in a variety of sizes and shapes, also depending on the breed of the chicken.