Flight of the Bumblebee
If chubby bumblebees try to fly by just flapping their
smallish wings or by keeping them stationary and using them to gain lift from
air currents like airplanes, they would crash to the ground. The wings are
too small in proportion to their body. Their anatomy seems so improbably
built for flight that the buzz among some people is that "we simply don't know
how bees do it." But we do. Bees gain lift by vibrating their wings up and
down about 200 times a second. That vibration, making the
characteristic buzzing sound, is accomplished by their thorax muscles. Musical
notes are created on string instruments also by vibration. For a demonstration
challenge, try vigorously moving your arms or legs (or both at the same time)
for at least 200 times in less than a minute (this exercise is not intended for
the faint hearted).
Bumblebees are found primarily in temperate regions
of the northern hemisphere, often ranging farther north and higher in altitude
than other bees. Fifty species of bumblebees are known in North America.
Colonies of bumblebees, unlike those of honeybees, only survive during the warm
season; new queens hibernate alone to begin another colony the following spring.
Bumblebees are among the few insects that can control their body temperature. In
cold weather, queens and workers can shiver their flight muscles to warm
themselves, allowing them to fly and work at lower temperatures than most other
insects. Their large size and heat-conserving hairy coats also help them stay
warm. These features enable them to live in northern latitudes and alpine
altitudes.