Scientists have found a way to use old crab shells to clean up toxic waste efficiently and inexpensively.

Even a Stone Age tribe would have had garbage, such as crab shells or scraps of food.

This left a crab shell made entirely of translucent chitin.

The shy animal would wait till overnight when no one was looking, and we'd find this little pile of crab shell in the morning.

The queen ran back to their rooms, saw the crab shell, and burned it.

Add the brown crabmeat and crab shells and cook for a further five minutes.

The noise turned out to be seagulls' dropping crab shells on the roof.

Within a minute, the crab shells had reddened.

A plating plant might need a few hundred pounds of the crab shells a year for waste-water treatment.

IN Maryland, crab shells are being turned into a natural insecticide.