A groundbreaking study led by University of British Columbia Ph.D. student, Hannah Griebling, reveals that raccoons (Procyon lotor) continue to engage with complex puzzle boxes long after securing their only marshmallow reward. This behavior suggests that these clever animals are driven by an inherent desire for information, a trait that may contribute to their remarkable adaptability in urban environments.

In this innovative study, Griebling and her team employed custom multi-access puzzle boxes equipped with various mechanisms, including latches, sliding doors, and knobs. These boxes featured nine entry points, categorized as easy, medium, and difficult.

During each 20-minute trial, the puzzle box contained a single marshmallow; however, the raccoons frequently pursued additional mechanisms even after consuming the treat, signaling their quest for knowledge.

“We were surprised to observe all three solution types being utilized in a single trial,” Griebling remarked.

“Even after the marshmallows were gone, they continued to tackle the puzzle.”

When faced with easier tasks, the raccoons explored multiple openings, mixing up their approach while covering a broad area.

As the difficulty increased, they favored reliable solutions but still demonstrated flexible problem-solving abilities, exploring various solutions even in the most challenging scenarios.

“This behavior highlights the classic trade-off between curiosity and potential risk,” Griebling noted.

Raccoons adapted their strategies based on perceived costs and risks, similar to decision-making patterns observed in other animals and humans.

“It’s akin to the common dilemma of choosing a dish at a restaurant,” Griebling explained. “Do you stick with your favorite or try something adventurous? If the risk is high—like an expensive meal you may dislike—you opt for the safe choice.”

“Raccoons tend to explore when costs are minimal and quickly play it safe once the stakes rise.”

This research sheds light on why raccoons thrive in urban areas. Their success can be attributed to cognitive and physical traits that make them well-adapted to city life.

With front limbs rich in sensory nerves for foraging in rivers, they are particularly skilled at manipulating locks and handles, often similar to those used by humans.

By solving problems related to information access—not merely food—raccoons gain advantages in complex environments, facilitating their ability to access trash cans and other food sources.

“Understanding cognitive traits that empower raccoons can inform strategies for managing struggling species and provide insights for other animals, such as bears, that utilize problem-solving to access engineered resources,” Griebling asserted.

The experiment was conducted with raccoons in a research facility in Colorado; however, earlier studies have indicated that wild raccoons exhibit comparable problem-solving capabilities, though researchers caution that their behaviors may differ.

“Raccoon intelligence has long captivated folklore, yet scientific research into their cognitive abilities remains relatively nascent,” stated Sarah Benson-Amram, also from the University of British Columbia.

“Research like this provides empirical validation for that reputation.”

The team’s results were published in the Journal of Animal Behavior on February 27, 2026.

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Hannah J. Griebling et al. 2026. Raccoons optimally gather information: The exploration-exploitation tradeoff in innovation. Animal Behavior 234: 123491; doi: 10.1016/j.anbehav.2026.123491.