Hydrophobicity refers to the property of a substance that repels water. Materials that are hydrophobic do not mix well with water and tend to form droplets instead. This characteristic is important in various fields, including biology and materials science, as it influences how substances interact with their environment. In nature, many organisms exhibit hydrophobic traits. For example, the leaves of the lotus plant have a special surface structure that makes them highly water-repellent, allowing water droplets to roll off and carry dirt with them. This phenomenon is known as the lotus effect and is studied for potential applications in creating self-cleaning surfaces.