OULU, FINLAND — Buff-tailed bumblebees can spontaneously roll a plastic foam ball under an artificial blue flower to use it as a ladder and reach a sugary reward. Researchers published these findings in the June 4 issue of the journal Science.
Olli Loukola, a behavioral ecologist at the University of Oulu, said, "Spontaneous problem-solving is something that has never been shown in any invertebrate before." Loukola added, "Our study is the first one where we can be 100 percent sure that these individuals don't have any prior experience about any problem-solving tasks." The researchers first taught the bees to associate movable balls and blue rings with food rewards. More than 70 percent of the tested bumblebees successfully retrieved the out-of-reach food by moving the ball.
Akshaye Bhambore, a doctoral researcher at the University of Oulu, said, "We showed for the first time that bumblebees can solve a completely novel object-manipulation task, spontaneously and without being trained to do so, or without any trial and error." The research team placed the insects inside circular plexiglass arenas, preventing the bees from flying. Researchers also divided the testing enclosures into two separate rooms with barriers, and the bees still located and retrieved hidden food. Bhambore said, "There was not much room for trial and error or playfulness in arenas with barriers." He added, "They had a goal in their mind, and they were able to understand the nature of the task."
James Nieh, a professor of ecology, behavior, and evolution at the University of California San Diego, wrote, "Bees do not normally move objects around to make platforms, so this is not a natural bumble bee behavior." Nieh also wrote, "But the experiment shows that they can remember a hidden goal location and manipulate an object in relation to that goal." In a control scenario where bees were exposed only to the flower but not the ball, the insects failed to solve the task. In a second control scenario where bees were exposed to neither the flower nor the ball, they also failed. Loukola said, "We need to get rid of the neophobia, or fear of new objects, by giving them the ball and showing that it is a safe object." He also said, "They also need the motivation, or the association between a reward and the blue of the flower, because if they don't have that, blue means nothing." Loukola concluded, "These two things together give them enough information to spontaneously solve the real problem, which is using the ball as a ladder to reach the blue flower."