Pyrethrin is a natural insecticide derived from the flowers of the chrysanthemum plant, specifically the species Chrysanthemum cinerariifolium and Chrysanthemum coccineum. It works by targeting the nervous system of insects, leading to paralysis and death. Pyrethrin is commonly used in agricultural settings and household pest control products due to its effectiveness and relatively low toxicity to humans and pets when used properly. However, it can be harmful to beneficial insects, particularly bees.