The horns are called ossicones. Male horns are larger than female. Females and young males have hair on top because males use their horns to fight and the hair is usually rubbed off the ends. Contrary to general belief, giraffes are not voiceless, but are in fact able to utter low moans and snorts. But noises apparently are not much used to communicate with each other.
Hearing is acute, sight excellent, but the acuteness of the sense of smell is questionable.
They have a wondernet below the brain which expands and reduces pressure when the giraffe puts its head down. At the same time, valves in the jugular vein close, trapping the blood and preventing it from flowing the wrong way. When the giraffe lifts its head, valves open and release the blood to continue circulating. Behavior They live in herds of from 2 or 3 to 70. Both forelimbs and both hindlimbs move together, instead of diagonally as a horse.