How Things Work: Bees

Credit: Michael Setzer/SciTech Editor Credit: Michael Setzer/SciTech Editor

Bees are a lot smarter than most people credit them. How do bees know where to find the best flowers? When they find these flowers, how do they tell other bees where they are? These are tasks that may appear trivial at first glance, but actually involve complex and miraculous processes. explains that bees use two main tools in their search for food: a solar compass and an internal clock. Bees use their solar compass to remember the location of objects relative to the sun. Since they are able to see polarized light, their solar compass is unaffected by whether it is a sunny or cloudy day. The second tool, a bee’s internal clock, keeps track of how long the bee has been searching for food.

What is amazing about the combination of these abilities is that bees are even aware of how the sun moves throughout the time that they are searching for food. This means that when the bee returns to its hive, it can tell its hive mates exactly where the food is relative to the current position of the sun — not just relative to where the sun was when it found the food.

LiveScience describes a new theory regarding how bees detect flowers: Most plants have a slight negative charge relative to the air around them, while flying bees have a positive charge. Wired explains the positive charge of bees by using the analogy of wings accumulating charge as they zip through the air the same way that electrical charge accumulates on a person shuffling across a carpet.

To test whether these opposite charges help bees locate flowers, researchers used artificial flowers, half of which were electrically charged and filled with sweet nectar, the other half of which had no charge and were filled with a bitter solution. As expected, the bees quickly learned that the good food could be found in the electrically charged sweet flowers.

But the real test came when the researchers switched off the electrical charges. When none of the flowers was electrically charged, the bees simply visited the flowers randomly. The results of this experiment suggest that bees do indeed use the electric charge of plants to find nectar-rich flowers. What’s more, biologists discovered that flowers that have already had their nectar harvested become more positively charged. This way, bees know not to waste their time visiting flowers that no longer have much nectar.

After locating where nectar-filled flowers are, bees need to communicate to their fellow hive mates where they are. explains that if the food is close to the hive, the bee will perform a round dance. This type of dance consists of traveling in loops in alternating directions. The round dance does not point in the direction of the food, it merely tells the other bees that food is nearby. When food is close, the other bees can usually find it on their own simply by using their odor senses.

A more complicated dance, which is performed when food is far away, is called the waggle dance. The waggle dance consists of flying in a straight line followed by returning loops. The direction of the straight line indicates the direction of the food in relation to the sun.

For example, if the bee runs straight up the hive walls, this means that the food can be found by flying toward the sun. Conversely, if the bee runs straight down the hive wall, the food can be found by flying away from the sun. The quality of the flowers are indicated by the speed of the returning loops.

The most important part of the waggle dance is the waggle run. As the bee flies its straight line and returning loops, it vibrates its wings and waggles its abdomen. By doing so, the bee moves the air around it, allowing other bees near it to learn the location of the food by the change in air movement.

Bees are not to be taken as mere insects — with solar compasses, internal clocks, electrical attraction to plants, and intricate dances, they are a highly efficient and cooperative species that find food and communicate in astonishing ways.