91Èȱ¬

Humans use tools to complete tasks every single day - and we are not alone in this.

Many other members of the animal kingdom, such as chimpanzees and dolphins, also make use of tools.

A new study has observed how sea otters regularly use tools such as rocks to break open hard shells so they can access the soft edible insides.

The use of tools to open shells also means they are less likely to damage their teeth.

Researchers observed the behaviour of 196 sea otters who live along the California coastline in the US.

They found that the otters used rocks, shells and even rubbish such as bottles as hammers to smash open any hard-shelled food such as crabs, mussels and snails.

They also sometimes bashed their prey onto hard surfaces such as boats to break open the shell.

This allows them to eat foods which they wouldn't be able to open using just their teeth.

Using tools otters are able to access more food, which is important for otters where food supplies might be limited.

It is also helpful for female otters, especially when pregnant, as they are able to take in more calories for growing their young.

Female otters were observed using tools more often than the males.

It especially important that the otters look after their teeth as they need them to survive.

Evolutionary biologist Chris Law, who led the study said: "Without their teeth, otters can't eat and will die. Females show slightly less damage to their teeth overall, probably because of their increased tool use".