The way squirrels organise their nuts will put your wardrobe to shame

Next time you lose your keys, think of a squirrel. The tiny animals have an incredible ability to remember exactly where they buried one nut weeks earlier, and new research is shedding light on how they do this.

Squirrels bury groups of nuts in particular places, meaning they will know where each one is buried, according to a new study.

In the same way as we may organise books, DVDs or jewellery into categories, the study found squirrels organise their nuts into groups. This behaviour, known as “chunking”, helps squirrels to remember where their nuts are while minimising the risk of their food being pilfered.

Chunking has long been thought to be a human trait, while research has also revealed rats and other animals can use it to aid recall. But this new study, published in the Royal Society Open Science, is one of the first times chunking has been seen in the wild by animals like squirrels, which belong to a group known as scatter hoarders.

The researchers, from the University of California Berkeley, tested a group of wild squirrels by giving them different kinds of nuts – almonds, hazelnuts, pecans and walnuts. They then mixed up the order of the nuts, and followed where the squirrels buried them.

Each time, no matter which order the nuts were given in, the squirrels buried the same type of nut in the same place.

“This first demonstration of chunking in a scatter hoarder underscores the cognitive demand of scatter hoarding,” the authors wrote in the paper. 

The squirrels became confused by the system, however, when the nuts were handed to them at different places. “Squirrels spatially chunked their caches by nut species but only when caching food that was foraged from a single location,” the authors said. 

But the squirrel’s chunking strategies might not be solely based on the species of nut. The study showed hints that the animals may categorise their findings into large and small, too.

“Squirrels may be chunking by item value, and this value may be derived from other factors as well as nut species, such as the weight of that individual nut,” the authors wrote. 

When you next go to organise your wardrobe, take some inspiration from your local squirrels.