Curious raccoons enjoy solving puzzles even without food reward, UBC study finds

A raccoon is seen interacting with a puzzle box. (Hannah Griebling)

Raccoons are known for their food-motivated antics, but a new study out of the University of British Columbia suggests it’s not always treats they’re after.

The study—published in the journal Animal Behaviour—found that while raccoons often outsmart latches and raid compost bins in search of food, they may also sometimes solve those puzzles simply for the challenge.

UBC said researchers conducted the study through a series of trials, in which they presented raccoons with a custom multi-access puzzle box that was equipped with latches, sliding doors and knobs.

The puzzle box had nine different entry points, ranging in difficulty from easy to hard. Raccoons were given 20 minutes in each trial to figure out how to reach a single marshmallow inside.

Researchers Hannah Griebling and Dr. Sarah Benson-Amram said the curious creatures continued to solve puzzles “long after” they retrieved the only food reward available.

“We weren’t expecting them to open all three solutions in a single trial,” Griebling said in a news release Monday. “They kept problem solving even when there was no marshmallow at the end.”

The study’s authors said this behaviour points to “intrinsic motivation” rather than hunger, describing it as “information foraging” because no additional food was given for continuing to solve the puzzle.

But the study found the animals didn’t approach every puzzle in the same way. When the challenge became more difficult, the raccoons tended to play it safe and rely on solutions they already knew worked.

However, some still explored multiple solutions even at the hardest level, according to researchers.

Griebling added that the pattern reflects a classic trade-off between curiosity and potential risk.

“It’s a pattern familiar to anyone ordering at a restaurant,” she said. “Do you order your favourite dish or try something new? If the risk is high—an expensive meal you might not like—you choose the safe option. Raccoons explore when the cost is low and quickly decide to play it safe when the stakes are higher.”

Researchers said those traits may also help explain why raccoons thrive in urban environments such as Vancouver.

“Their forepaws, rich with sensory nerves for foraging in streams, are well-suited to manipulating latches and handles—often the same kinds used by humans,” the study reads.

“Solving problems for information, not just food, may give them an advantage in complex environments, helping them access garbage bins or other food sources. Vancouver’s greenspaces, waterways and generally tolerant public provide near-ideal habitat.”

Griebling added that studying the cognitive traits which allow raccoons to thrive could help guide the management of other species that struggle to adapt to human environments, like bears.

The experiment involved captive raccoons at a research facility in Colorado, although previous research suggests wild raccoons show similar problem-solving abilities. However, researchers said the behaviours may not be identical.

“Raccoon intelligence has long (been) featured in folklore, yet scientific research on their cognition remains limited. Studies like this provide empirical evidence to support that reputation,” Dr. Benson-Amram said in the release.