(Melissa asking Shaun what a Salt Lick is. - The Estate (Chapter 14 Cleveland Revenge))Edit
A mineral lick (also known as salt lick or natural lick) is a natural mineral deposit where animals in nutrient-poor ecosystems can obtain essential mineral nutrients. In an ecosystem, salt/mineral licks often occur naturally, providing the sodium, calcium, iron, phosphorus and zinc required in the springtime for bone, muscle and other growth in deer and other wildlife, such as moose, elephants, tapirs, cattle, woodchucks, domestic sheep, fox squirrels, mountain goats and porcupines. Harsh weather exposes salty mineral deposits that draw animals from miles away for a taste of needed nutrients. It is thought that certain fauna can detect calcium in salt licks.
[Note] Just like us, horses need certain minerals to stay healthy. Most horses today are not kept in places where they could find these minerals on their own. So owners must provide salt for their horses just like they provide food and water.