http://youtu.be/6TTA7JMSPY4
Pyrethrins are one of the oldest known insecticides and are derived from dried and crushed flower heads of two species of asters: Chrysanthemum cinerariifolium and C. coccineum. Synthetic pyrethroids are a mixture of six chemicals that are toxic to insects. Pyrethrins are commonly used to control mosquitoes, fleas, flies, moths, ants, and many other pests. Pyrethrins are generally separated from the flowers. However, they typically contain impurities from the flower. Whole, crushed flowers are known as pyrethrum powder. Pyrethrins have been registered for use in pesticides since the 1950’s. Currently, pyrethrins are found in over 2,000 registered pesticide products. Many of these are used in and around buildings and on crops and ornamental plants. Pyrethrins are commonly found in foggers (bug bombs), sprays, dusts and pet shampoos. Some of these products can be used in organic agriculture. Pyrethrins excite the nervous system of insects that touch or eat it. This quickly leads to paralysis and ultimately their death. Pyrethrins are often mixed with another chemical to increase their effect.