Mosquitoes typically breed and lay their eggs in water clogged with such vegetation as algae, waterlettuce, hydrilla, waterhyacinth, and cattail, authors Patrick O'Connor-Marer and Kathy Keatley Garvey wrote in their book, Aquatic Pest Control. This is a close-up of algae in a fish pond. (Photo by Kathy Keatley Garvey)