Lots of young mammals and birds engage in behaviour that provides no obvious adaptive outcome such as access to food, shelter or a mate, is voluntary and rewarding in itself and appears to be conducted pleasantly when the animal is relaxed.

What about bumblebees (大黄蜂)? Apparently they play too, according to work just published in Animal Behaviour by Galpayage Dona and Lars Chittka. The idea of asking whether bumblebees like to play came to Chittka during a previous study in which he trained them to roll wooden balls around in order to gain access to food. He noticed that, during this experiment, they would often roll the balls for no apparent reason. They just seemed to enjoy it.

A perfect PhD project for an ambitious student. And Ms Galpayage Dona stepped up to the mark. She created an field, put pollen (花粉) and sugar solution in it to arrest the bees, and connected it via a plastic tube to a bumblebee nest in Dr Chittka’s laboratory. In one part of the field, nine of the balls were fixed to the floor. In another, the balls could be rolled around. Ms Dona tagged 45 bees, between one and 23 days old, so that they could be followed as individuals. She then opened the door to the field for three hours a day for 18 days and recorded on video what happened.

The recordings suggested that the bees did enjoy this experiment. All of the tagged bees rolled a ball at least once during the experiment. Most did so many times. One particular enthusiast managed 117 rolls. Overall, the camera recorded 910 incidents of ball—rolling by tagged insects. Also young bees played more often than old ones. All that they seemingly need now is some goalposts and a referee (裁判), and bumblebee social behaviour will take off to the next level.

【小题1】Why do some animals engage in the behavior mentioned in paragraph 1?

A．To find a perfect mate.	B．To gain access to food.
C．To entertain themselves.	D．To get rewards from others.

【小题2】What gave rise to the study published in Animal Behaviour?

A．A survival training	B．A failed experiment.
C．An ambitious project.	D．An unexpected finding.

【小题3】What does the underlined phrase “stepped up to the mark” mean in paragraph 3?

A．Applied for her PhD.	B．Joined Chittka’s study.
C．Tagged the bumblebees.	D．Updated Chittka’s equipment.

【小题4】What can be a suitable title of the passage?

A．Why Animals Love to Play?	B．How Bumblebees Manage Ball-rolling?
C．Are Bumblebees Porential Football Players?	D．Is Playfulness Restricted to Mammals and Birds