* To remove velvet: The velvet covering their antlers is a soft, fuzzy layer that helps the antlers grow. As the antlers mature, the velvet begins to dry and peel off. By rubbing their antlers against trees, deer help to scrape off the velvet and expose the hard, bony antlers beneath.
* To mark territory: The scent glands in deer's antlers release pheromones when they rub against trees. This helps mark territory and attract mates.
* To sharpen their antlers: The rubbing action helps to sharpen and polish the antlers, making them more effective weapons for fighting and defense.
* To relieve itching: The velvet can be itchy as it dries and peels off. Rubbing against trees helps to relieve this itching.
Interestingly: The rubbing action can also leave a distinctive scent mark on the tree, as well as create a visual mark that can be seen by other deer. This helps to establish dominance and communicate with other deer in the area.