| You've been reading about animal behavior. |
| Today we'll discuss one of the most astonishing behaviors in the animal world: dancing bees. |
| Did you know that bees can dance? |
| Well, neither did scientists, until the 1960s. |
| That's when a German scientist, named, uh, Karl von Frisch, |
| noticed something truly remarkable. |
| As he was observing honeybees, |
| he noticed that some of the bees, which he called scout bees, |
| flew out of the hive to look for food. |
| When a scout found a site where there was food, |
| it flew back to the beehive and started dancing. |
| This dance somehow told the other honeybees where the food was, |
| because after the dance, the bees... some of the bees flew from the hive straight to the site of the food. |
| Von Frisch called the bees that collect the food forager bees. |
| He thought the scout bee's dance told the forager bees three things: |
| first, the smell of the food it had found; |
| second, which direction to fly to reach the food; |
| and third, the distance of the food site from the beehive. |
| Von Frisch won the 1973 Nobel Prize for this discovery, |
| but many scientists were skeptical of his theory. |
| They didn't believe it was the dance that led the forager bees to food. |
| Instead, they thought it might be, oh, the smell of the food on the dancing bee, |
| or maybe that they just followed the scout back to the food site. |
| Well, very recently, some British scientists used a new type of radar |
| to prove that von Frisch's theory was indeed correct. |
| It is the dance that communicates this information to other bees. |
| British researchers found that the scout bees perform two types of dances. |
| If the food is near the hive, say, oh, about 50 or 60 meters away, |
| the scout flies in a round pattern, like a circle. |
| This tells the location, but not the direction, of the food site. |
| If the site is farther away, |
| the scout does what's called a waggle dance. |
| It flies in a pattern of ovals and vertical lines. |
| The speed of the waggle dance tells other bees how far away the food site is. |
| The slower the dance, the farther away the food. |
| If the scout flies in a vertical line up the side of the beehive, |
| it's telling the foragers to fly directly toward the sun. |
| If the scout flies vertically down the hive, it's saying, "fly away from the sun". |
| Up is toward, down is away. |
| If the scout flies at an angle to the hive, |
| it's telling the foragers to fly neither toward nor away from the sun, but in between. |
| The bees have a special internal mechanism to know which angle they should fly, |
| based on the sun, the hive and the food site. |
| They can also measure the distance they fly by recording the motion of things they see as they fly past. |
| Now, um, one problem with von Frisch's theory had been this: |
| It seems to take the forager bees a long time to reach the food site. |
| That's why scientists thought that perhaps it wasn't the waggle dance that led them there. |
| For many years, scientists couldn't follow the foragers after they left the hive |
| because they didn't have the technology. |
| Just a few years ago, though, |
| the British scientists solved this problem using a new type of radar. |
| They were able to attach a... a small radio transmitter to forager bees, |
| I don't know how, but they did. |
| This enabled them to follow the forager bees' flight after they left the hive. |
| The radar showed that foragers, do, in fact, fly straight to the area of the food site. |
| They don't follow the scout bee back to the site, |
| because the scout goes into the hive after it finishes dancing. |
| Well then, if the waggle dance does lead the foragers directly to the food site, |
| why does it take so long for them to find the actual food? |
| The answer is that the waggle dance leads the foragers only to the general area of the food. |
| It doesn't tell them the exact location of the flowers or plants that have the food. |
| So the foragers have to spend a while flying around the area |
| before they find the exact location of what they're looking for. |