Bees are winged insects that evolved from wasps. It is believed they originated in Southeast Asia; there are some 20,000 known species; they are found worldwide wherever there are insect-pollinated flowering plants. Some bees are solitary, but varieties such as the honeybee live in colonies. Bees consume pollen and nectar and are responsible for pollinating the plants and trees we use for food and for creating hives that produce nutritious honey. Although bees can produce a painful and sometimes deadly sting, they are generally non-aggressive if undisturbed. Since 1972 there has been an alarming reduction of honeybees in the United States due to viruses and parasites. The increased use of pesticides is also suspected of contributing to their decline.