Deer lick salt because salt supplements their diet, providing nutrients and minerals missing in other food sources. These includes magnesium, sodium, calcium, phosphorus and zinc. Lactating females require salt, as do young bucks for the purpose of antler growth.
Salt licks are most popular with deer in the early summer months of June and July. State laws often regulate the setting out of salt licks to attract deer for hunting; doing so is sometimes considered an illegal form of baiting. Salt for salt licks is sold in either block or granular form. The granular form packed in bags is the more popular variety.