For the second time this year, bumblebees have stepped up to scientists' tests and shown that they can solve cooperative tasks that transcend their tiny brains.

In a series of lab experiments, bumblebees (Bombus sp.) that trained together on tasks to retrieve a sugary reward were more likely to wait for their partner before returning to the task than bees that trained alone.

"The study's findings challenge conventional notions of insects, and the ability to work together towards a common goal is present even in the miniature brain of bumblebees," says Olli Loukola, lead author of the study and behavioral ecologist at the University of Oulu in Finland.

The findings come amid a growing awareness of possible insect consciousness and follow demonstrations of human-like collective intelligence in bumblebees, specifically.

Cooperation is a facet of social behavior that shows an awareness of and collaboration with others.

With their bee experiments, Loukola and colleagues wanted "to probe whether behaviors in cooperative tasks represent individual efforts, a simple recognition of partner presence, or a deeper understanding of roles and goals."

These are three of four different types of cooperative behavior that biologists have recently defined, to better delineate between them.

Chimpanzees, dolphins, wolves, and birds have all been seen working together towards a shared goal, with the fourth type of cooperative behavior held up as a hallmark of human cooperation and rarely seen in non-human animals.

Compared to big-brained animals, not much has been expected of bumblebees. However, recent lab experiments show they should not be underestimated: bees can learn step-wise tasks, teach others to solve problems, wield tools, count to zero, and even crunch basic mathematical equations.

Loukola and colleagues found that when a bee's partner was held back from entering a test arena, they took longer to first push the block or door than control bees that learned to push alone and who got straight to work trying to access their reward unaided.

As you can see in the video below, a bumblebee waits for its training partner to arrive before the two insects proceed to move the Lego block to slurp up their sugar water reward.

In other tunnel experiments, bees hesitated at a door concealing their reward until their training buddy arrived or turned back towards the door after going in search of their partner once their partner appeared in the adjacent tunnel.

"These results show that bumblebees' cooperative behavior is not simply a by-product of individual efforts but is socially influenced," Loukola and colleagues write in their paper.

"If bees' coordination went beyond social influence," the researchers continue, then "we should have observed attempts to somehow facilitate coordination."

But that was difficult to discern, Loukola and colleagues admit. Bees that turned around in the tunnel might have been 'recruited' by their partner to the task of opening the door, although it could just be that the bees selfishly associated the presence of another bee at the door with accessing their sugary reward.

"Whether bumblebees truly understand the role of their partner will require further research with more detailed monitoring of their behavior during cooperation," Loukola says.

This could be done, like it has been previously with dolphins, by requiring bees to synchronize when they push a button to obtain a reward.

In the meantime, it's intriguing to consider why bumblebees might have developed this capacity for cooperation, because as the researchers note, bumblebees tend to operate as lone rangers when foraging in the wild.

It's possible that cooperative behavior is widespread across the animal kingdom simply to aid survival when it counts.

The research has been published in Proceedings of the Royal Society B.