Humans aren’t the only animals that can use tools to get a job done — sea otters have been utilizing tools for possibly millions of years.

That’s the assertion of a study in Biology Letters, which compared the genetics of California sea otters and Indo-Pacific bottlenose dolphins that use tools. Why those two animals? Because the otters and the dolphins use tools in similar ways: While not all members of the populations rely on tools, they use them when they need help getting at food, among other behavioral overlaps.

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“Sea otters use rocks or other hard objects to break open well armoured prey such as marine snails,” the study offers as an example. “Dolphins use conical sponges as tools to protect their sensitive snouts while probing among rocks for small, burrowing fish that live at the bottom of deep ocean trenches.”

Despite those outward common traits, the researchers say the analysis showed that the two animals have distinct genetic patterns. Although the dolphins that use tools are more genetically linked to one another than to their brethren that don’t, the sea otters did not have any more DNA in common with their fellow tool-users than they did with other otters. That suggests dolphins may have only figured out how to harness tools within the last 200 years perhaps, while sea otters “have probably been using tools for many thousands or even millions of years.”

The study points out that there’s more evidence to support that idea in the fact that otter orphans brought up in captivity have not had a mother to teach them to use tools but they still “exhibit rudimentary pounding behaviour” — the behavior is more innate than what is seen in dolphins.

It’s not just marine animals that can use a tool to get the job done. Chimpanzees, which are one of the most closely related primates to humans, will use twigs to reach termites in spaces their hands can’t reach or grab a rock to open a nut, the BBC says. The chimps also make weapons, like throwing a stick at their adversaries or hunting with a rudimentary spear.

Crows can use twigs, leaves or feathers as tools, and polar bears in zoos “often throw objects with great force and accuracy,” NPR notes. “It's less clear whether this sort of tool use occurs in the wild. But there are anecdotal reports from early Arctic explorers of polar bears using projectiles to hunt.”

See also:

Can Chimps Live As Long As Humans?

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