Reptiles and amphibians are important second-and third-level consumers in the food-chain, regulating populations of small mammals, birds and invertebrates. This regulatory function has economic importance in controlling rodent and bird pests of crops and granaries. Aquatic amphibians control malaria by feeding on mosquito larvae. Crocodile farms provide sustainably harvested meat to restaurants and leather for goods such as handbags, belts and shoes. Large turtles are important marine herbivores along the Kenyan coast. Poisonous snakes are a threat to human life and may account for more deaths than any other wildlife, but are also a major attraction at snake parks. Snake venom is the subject of immunological and biomedical research. Amphibians are widely used in teaching anatomy and physiology in secondary and tertiary education, and are a sensitive biological indicator of agrochemical pollutants that damage ecosystems and people.