Sea otters use tools to open hard-shelled prey, saving their teeth, research reveals

The behavior, documented in footage from researcher Chris Law, is most seen in females and sheds light on the threatened species

Floating on its back in the waters of California's Monterey Bay, a sea otter takes a shelled animal and strikes it against a rock sitting on its chest to break open the prey.

This behavior, documented in footage from researcher Chris Law, is seen in relatively few animals and allows the otter to access food without damaging its teeth. A new study, which will be published in the journal Science on Friday, sheds light on the threatened species' tactics.