Warts are hard, benign growths on the skin caused by a viral agent. Verrucas are a type of wart that appears on the toes and soles of your feet. Because warts are caused by viruses, they are contagious. There are many methods to remove warts. One of them, electrosurgery, utilizes a pen-like device that electrocutes the cells in the wart. Surgical excision may also remove them if the warts are particularly large.