Antlers grow annually from the pedicle of the frontal bone of male deer. They are male secondary sexual characteristics, hence are only grown by stags, although in the wider Cervidae family, they also grow in female reindeer (also known as 'caribou' in North America). Antlers are quite unlike the horns of cattle, which do not regrow if removed correctly. Antlers also develop and mature in a manner different to horns and broadly two stages of antler development are recognised: velvet antler and hard antler.
Velvet antler is defined as growing antler which contains an abundant blood and nerve supply and which has a fully intact skin with a covering of soft fine hair. Hard antler is the antler when growth has ceased, calcification has occurred, and the skin, nerve and blood supply are no longer functional.
Velvet antlers grow very rapidly, at a rate of up to 2cm a day.
The male deer of most species develop a pair of antlers every year from bony outgrowths called pedicles.
In respect of dominance, the stag with the largest antlers tends to be dominant.