Sea otters are known for using tools, but not all of them do. A new study finds those that use tools have better survival odds in a world where their traditional food sources are changing.

Sea otters present a special challenge for archaeologists, though. Otters drop their tools and the smashed shells into the ocean when they’ve finished.

Some otters rely on tools to bust open hard-shelled prey items like snails, and a new study suggests this tool use is helping them to survive as their favorite, easier-to-eat foods disappear.

Some otters rely on tools to bust open hard-shelled prey items like snails, ... Some otters rely on tools to bust open hard-shelled prey items like snails, and a new study suggests this tool use is ...