Chickens, like all birds, are visually oriented. The size of the eyeball permits visualization of a relatively large image. This accounts for the ability of chickens to see even the tiniest food particles, like seeds. Chickens do not hear as well as they can see, but their ears are reasonably well developed and useful. They do not have an external ear, but rather a round opening that is surrounded by a disc and hidden by tiny feathers.
Chickens communicate by voice and gestures.
Crowing announces the morning just at the break of dawn. The hen's loud, excited cackle announces an egg just laid. Clucking sounds are the distinctive voice sounds of a broody hen and the contact assurance of a mother for her chicks. Chickens require light, warmth, and shelter from wind and drafts. Despite their love of warmth, chickens tolerate heat poorly, since they have no sweat glands to allow perspiration.