Why Otters Juggle Rocks: 4 Surprising Cases of Animal Tool Use

Animal intelligence research might as well be described as the history of humans realizing we’re not as special as we think we are. Tool use, once believed to be exclusively a human ability, is just one example.

It’s a wide world out there, and many of our animal cousins — and not necessarily close cousins! — have been known to use objects in creative and purposeful ways.

1. Capuchin Monkeys Have Entered the Stone Age

Last year a group of capuchin monkeys on a remote island of Panama made headlines when scientists discovered they regularly use stone tools to overcome the natural defenses of clams and hard nuts.

Capuchins aren’t the first non-human primates to do so, but they’re a particularly good example because they demonstrate all the hallmarks of true tool use. Some species of sea birds are known to drop clams from great heights to smash their shells, but capuchin monkeys collect and carry stones great distances — and not because they have an immediate use or value in and of themselves. These tools can help the monkeys attain something of value later: an otherwise inaccessible food source.

This learned behavior suggests forethought, as well as a grasp of the idea of extending one’s abilities beyond one’s physiological limitations.

2. Octopus Building Its Own Defensive Gear

A paperback about an octopus and a coconut got a lot of attention as the first known example of tool use in an invertebrate. The octopus was caught on camera using two sunken coconut shell halves as a makeshift shell.

Similar to the capuchin monkeys, the critical point was that the octopus had to think ahead and gather an object that was not immediately useful but would benefit the animal in the future. Critically, the two coconut shell halves, gathered separately, only worked as a defensive tool once the octopus had gathered two of them — making this example more complex than the use of a single stone.

3. Bottlenose Dolphins Protecting Said “Nose”

I’ve heard arguments that the intelligence of whales and dolphins cannot be easily compared to land animals because the environment is so different. Even if it turned out that cetaceans had comparable cognitive abilities to human beings, we can’t expect them to build cities or domesticate the jellyfish.

Many of the major human technological landmarks — like fire, the wheel and written language — simply aren’t possible underwater. But if some tool use is still possible for marine animals, it’s not surprising that dolphins have discovered it.

Dolphins lack hands, or any dedicated highly prehensile organ, but they do rely on their sensitive rostrums — their beak or, superficially, something like a nose — to root around for food along the sandy seafloor. However, this comes with risks — like encountering sharp, pointy or otherwise dangerous objects.

So, just as humans wear thick gloves to protect their hands when reaching into the unknown, bottlenose dolphins have been known to collect and wear sea sponges prior to doing any digging.

4. Otter Stone-Juggling

Unlike primates, cephalopods and cetaceans, otters don’t regularly make “world’s smartest animals” lists. They’re cute, however — and their playfulness, including floating on their backs and juggling stones, is just adorable. But it turns out this is connected to tool use.

Sea otters make use of their hand-like appendages to gather stones and food sources like clams. Floating at the surface of the water on their backs, they use the stones to break open the clams and get at the food inside.

Doing so underwater might be easier, but managing enough speed to get the necessary impact force would be harder. So otters balance these objects at the surface — and the juggling during their free time is essentially tool training to build up the balancing skills and muscle memory to use their tool correctly.

Yes, otters attend trade school.

Interestingly, otters also become very attached to their particular stones, carrying them for their entire lifetimes to use again and again.

Photo credit: Marshal Hedin

118 comments

Peggy B
Peggy B1 months ago

Wow

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Caitlin L
Past Member 2 months ago

thanks very much

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Helen C
Helen C2 months ago

They are wonderful, cute ,smart & so entertaining.....

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joan silaco
joan silaco2 months ago

thank you

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Chad Anderson
Chad Anderson2 months ago

Thank you.

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Hannah A
Hannah A2 months ago

tyfs

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Ruth S
Ruth S2 months ago

Thanks.

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Ruth S
Ruth S2 months ago

Thanks.

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Leo C
Leo Custer2 months ago

Thank you for posting!

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Peggy Peters
Peggy Peters2 months ago

Humans do not have the exclusive on tools; just an FYI.

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