Jenny Marie Eskew, age 11, of Wheeling, i7. Virginia, for her question:
How do bees hum?
Very early in the spring, the bees from a neighbor's hives hum softly among Andy's almond trees. Later they arrive right on time to buzz through the apricot blossoms, next they take a turn through the fragrant pink apple blossoms. Then the papery white pear blossoms are open and ready to welcome the buzzing bees. Naturally they are busy collecting sweet nectars and dusty golden pollens. They pay for these groceries by fertilizing the flowers so that nuts and fruits can mature through the summer.
The Mariner space probes pack an amazing amount of sophisticated equipment into a very small package. But they cannot compare with the small miracle we know as an ordinary bee. She is a living miracle of biological equipment, guaranteed to work with accuracy at high speed in many different situations. Her soft sweet humming sound is a sort of by product of her speedy little wings.
A furry little bee has four gauzy wings, two attached to each shoulder. If all four of them were separated and spread flat, they would hardly cover one of your finger¬nails. Their thin gauzy material is reinforced with networks of delicate veins, but those little bee wings look far too fragile for heavy duty. But this is not so, for they can beat fast enough to create a hum somewhat like a miniature electric fan.
This is possible because they work together with remarkable precision. The two wings on each side are designed to work as one, in perfect harmony with the two on the opposite side. Though they can be separated for cleaning purposes and when the bee stands or walks, they are linked together in flight.
The inside edges, between the two wings on each side, have a built in locking system. Each front wing has a series of little hooks and each back wring has a series of tiny grooves. When the bee takes to the air, the two wings on each side are inter¬locked and beat as one. And they beat at top speed in perfect harmony, usually about 400 times a second.
This speedy action is much too fast for our eyes to follow, especially when the tiny beaters are made of almost transparent material. All tae see is a hazy blue. But the tiny wings whip up tiny air currents which create the gentle hum we hear when the bees are busy in the harden.
A bee can fly forward or backward or hover like a fairy helicopter. When visiting from flower to flower, she usually flies in figures of eight. But often she flies a strai;ht course from the hive to the flowers. And when her tummy is full of nectar and her baskets are full of pollen, she always flies a straight bee line home to the hive. Her top speed is about 12 miles an hour with 400 whirring cningbeats to the second.