Playing is human nature, and this instinct is found in both mammals and birds. British scientists found that bumblebees spontaneously roll small balls in experiments, which is the first time to prove that insects also have game behavior. Relevant papers were published in Animal Behavior on October 19. In 2017, a study found that bumblebees can learn to roll small balls through training under the reward of honey. This is the first time that scientists have found that insects can learn skills that are not necessary for survival. Inspired by this, the Samadi Galpayage team of Queen Mary University in London began to study whether bumblebees could spontaneously produce game behaviors without rewards. To test this idea, the team started a new experiment. The researchers marked 45 yellow tailed bumblebees of different ages and sexes and created a passage for them from the hive to the feeding area. On both sides of the channel, the researchers placed 18 colored wooden balls. The wooden ball on one side of the channel is fixed on the ground, and the wooden ball on the other side can roll freely. In order to accurately capture the potential motivation of bumblebee's rolling ball, the researchers ensure that the rolling ball has no effect on its behavior of obtaining food, cleaning up debris, mating, etc. During the 18 day experiment, the researchers opened the channel for 3 hours every day. It was found that the frequency of bumblebee entering the rolling sphere region was 50% higher than that of the fixed sphere region. During the whole study, each bumblebee rolled the ball from 1 to 117 times. Gordon Burghardt, a professor at the University of Tennessee who was not involved in the study, said: "If you see a behavior similar to a bumblebee rolling a ball on a dog, a monkey, or even a bird, you will not hesitate to call it a game." There are age and sex differences in the behavior of bumblebee rolling ball. Young bumblebees tend to roll ball more than older bumblebees; At the same age, male bumblebees spend more time rolling ball than female bumblebees. Galpayage, the corresponding author of the study, said that just like cats and dogs develop hunting skills through fighting and wrestling, games are particularly beneficial to young bumblebees in terms of spirit and physical strength. Galpayage said that because the ball rolling seems to be spontaneous and voluntary, it has no direct or long-term benefits for insects, so they may just do it for fun. She added that for humans, you can ask "Are you enjoying yourself?" But for animals, it is difficult to evaluate. (Outlook New Times)