Scientists in Britain have managed to teach bumblebees(大黄蜂) to pull strings to get to food and then pass on what they have learned to others in their colony(群体)—showing a high level of intelligence despite their tiny brains.

Researchers at Queen Mary University of London said the experiments, often used to test the intelligence of apes(猿) and birds, showed for the first time that some insects are up to the task, and can also pass skills on through several generations.

The findings add to the evidence suggesting the ability for “culture spread”--the ability to learn and pass on knowledge and skills--may not be exclusive to humans.

In the research, published in the journal PLOS Biology on Tuesday, the scientists were able to train 23 out of a group of 40 bees to pull strings with their legs and feet.

The strings were attached to discs--or artificial “flowers”--containing food at their center but placed under a transparent screen. The bees, spotting the food beneath the screen, learned to pull the “flowers” out by pulling the string with their legs and feet to be able to get to it.

From another group of bees given the chance to solve the task without any training, only two of 110 were successful.

Another group of bees was then allowed to observe the trained bees pulling the strings, and 60 percent of them successfully learned the skill. Finally, trained bees were put in colonies, and the scientists found the technique spread successfully to a majority of the colony’s worker bees.

Lars Chittka, a Queen Mary University professor who guided the project, said the team is interested in figuring out the brain processes behind the bees’ learning and teaching skills.

From old times, crows (乌鸦) have been famous for their cleverness. They use tools, work out problems, and even enjoy playing. 【小题1】

To make tools, crows cut off leaves with their ''mouths'', shape them, and use them to look for bugs in wood or plants. 【小题2】When the leaf isn't needed for the moment, the bird stores the tool at its feet or somewhere else.

To test wild crows' abilities to work out problems, scientists placed food outdoors in covered bowls. They watched with interest as the birds smartly opened the bowls to get the food. Scientists also found out that crows can make use of the traffic. 【小题3】.

【小题4】Young crows will carry a stick or nut into the air, drop it, and fly to catch the object as it falls.

So just how smart are crows? Perhaps a crow will never do tricks as a dog will. 【小题5】

Music tends to get stuck in our heads. Sometimes a tune(曲调) stays on our thoughts and then plays, and replays, which seems never to end. This interesting phenomenon, commonly called “earworm”, becomes a subject explored by scientists. Earworms can run around our heads from several minutes to numerous hours. As the melody (旋律) repeats, it becomes stuck in our mind. Even though our ears do not hear the tune, our brain continues to play it.

Earworms often take the form of song pieces rather than entire songs, and the song is usually a familiar one. Researchers are uncertain why some songs are more likely to get stuck in our heads than others, but everyone has their own tunes. Often those songs have a simple, pleasant melody and charming, repetitive lyrics (歌词), such as popular commercial jingles and slightly annoying radio hits. Recent or repeated exposure to a song or even a small part of a song can also cause earworms, as can word associations, such as a phrase similar to the lyrics of a song.

While earworms might be annoying, most people report they are pleasant or at least neutral(中立). Only a third of people are disturbed by the earworms. How people deal with their earworms depends on how they feel about them. Those with positive feelings about their stuck songs prefer to just “let them be” while those with negative feelings turn to more behavioral responses, such as singing, talking, or even praying. They are also looking at whether everyday strategies help, like going for a run or doing a crossword. For them, getting an unwanted tune out of their head is a relief. But of course the song that cures you might just end up being the next one that gets stuck.