NYS Grade 8 Practice Test 12

The Dance That Gives Directions

¹A honeybee that finds a rich patch of flowers faces a problem. The flowers may be a mile or more from the hive, and the bee has no map, no words, and no way to point. Yet soon after she returns home, dozens of her sisters may be flying straight to the same flowers. For centuries, beekeepers noticed this happening without knowing how it worked.

²The answer came from the Austrian scientist Karl von Frisch, who spent decades studying honeybees. In experiments carried out over many years and described most fully in the 1940s, von Frisch set out dishes of sugar water at measured distances and directions from his hives and marked the bees that visited them with tiny dots of paint. Then he watched what the marked bees did when they returned. Through a glass-walled hive, he saw them perform a strange, repeated dance on the upright surface of the honeycomb.

³The most important part of the dance is called the waggle run. The bee walks forward in a straight line while shaking her abdomen rapidly from side to side. Then she circles back to her starting point, first to one side and then to the other, and repeats the waggle run again and again. Von Frisch discovered that this simple-looking performance carries two pieces of information.

⁴The first is direction. Inside the dark hive, the bee uses the direction straight up the comb to stand for the direction of the sun. If the food lies directly toward the sun, she waggles straight up. If it lies 40 degrees to the right of the sun, she waggles at an angle 40 degrees to the right of straight up. The other bees, crowding close and following her movements in the dark, sense the angle and translate it back into a flight path once they leave the hive.

⁵The second is distance. The longer each waggle run lasts, the farther away the food is. For food very close to the hive, the bee performs a simpler, circling version of the dance. The dancer also carries the scent of the flowers on her body, which helps the other bees recognize the right blossoms when they arrive.

⁶Many scientists at first found von Frisch's claims hard to believe. The idea that an insect could communicate something as abstract as an angle seemed impossible. But other researchers repeated his experiments and reached the same results, and later studies that used radar to track bees in flight confirmed that bees that had followed a dance flew toward the location it described. In 1973, von Frisch shared the Nobel Prize in Physiology or Medicine for his work on animal behavior.

⁷Von Frisch's discovery changed the way people thought about animals. It showed that even a creature with a brain smaller than a sesame seed can share precise information, and that patient, careful observation can reveal languages we never knew existed.

Bees on the Rooftops

¹Look up the next time you walk through Manhattan, and you might be looking toward a beehive. On rooftops above hotels, restaurants, schools, and apartment buildings, New York City is home to hundreds of honeybee hives. Honeybees were not always welcome here. Until 2010, keeping them was against the city's health code. That year, the city changed the rule, and beekeepers who had been working quietly could finally register their hives in the open.

²Why would anyone keep bees in one of the most crowded cities on Earth? Surprisingly, cities can be good places for bees. Parks, community gardens, window boxes, and street trees bloom at different times through the spring and summer, giving bees a steady supply of food. The city's linden trees, which flower in early summer, are a particular favorite. Honeybees typically forage within a few miles of their hive, so a single rooftop colony can visit thousands of blossoms across many city blocks.

³Beekeepers describe the work as a lesson in paying attention. Before opening a hive, they watch the entrance: bees streaming out in the morning and returning with their legs packed with yellow or orange pollen. A beekeeper learns to read the hum of a healthy colony and to notice when something sounds wrong. The first time I helped a friend inspect her rooftop hive, she told me, "After a while you stop seeing a box of insects. You start seeing a city inside a city."

⁴Rooftop hives also give city residents a rare close look at where food comes from. Bees pollinate many fruits and vegetables, including squash, apples, and cucumbers, and a hive near a community garden can help those plants produce. Schools with hives use them to teach students about biology and the environment. In the fall, some rooftop beekeepers sell or give away jars of their honey at neighborhood markets, letting customers taste the flowers of their own streets.

⁵Still, rooftop beekeeping is not simply good news. Honeybees are not native to North America; European colonists brought them in the 1600s. New York is also home to more than 200 species of native bees, many of them small, solitary bees that nest in the ground or in hollow stems. Some ecologists worry that when too many honeybee hives are packed into one area, the honeybees may compete with native bees for the same limited flowers. Planting more flowers, not just adding more hives, may be the best way to help all of the city's bees.

⁶For now, the rooftop hives keep humming. Each summer, beekeepers lift the lids, puff a little smoke to calm the bees, and pull out frames heavy with honey, proof that even in a city of concrete and steel, a colony of tiny insects can find what it needs to thrive.