Zoo animals baffled by cardboard boxes

Workers at Denver Zoo gave a number of animals cardboard boxes as an end-of-year treat and to engage their curiosity.

The footage, shared by the zoo on December 26, shows Yuri the Amur tiger, Zara the fennec fox, Tavi the spotted hyena, and Bungee the spider inspecting and playing with the boxes.

According to zookeepers, cardboard boxes act as a form of enrichment as it allows animals to tear up materials that would have otherwise been disposed of.

"They stimulate foraging behaviours for hidden food, and they're biodegradable," the zoo wrote in a Facebook post.