Hydrophobic literally means afraid of water. Hydrophobic substances are those that are insoluble in water. Hydrophobic substances are typically those that have no charged poles in their molecules. Many common hydrophobic substances are oils, fats, etc. When placed in water hydrophobic substances typically clump together, whereas hydrophilic substances (water-loving) dissolve. In nature hydrophobic materials are used for all kinds of purposes. In the photo above the fire ants shown all have an extremely hydrophobic exterior that does not let water in. This allows them to create a bubble of air around them when pushed underwater collectively.