Desert locusts’ jaws sharpen themselves, Northeastern materials scientist discovers - Northeastern University College of Science

Sharks lose teeth all their lives, replacing them in a kind of endless rotating Rolodex, while humans, of course, get only our two sets. Beavers’ teeth, notoriously, grow all their lives and have to be worn down to prevent injury.

New research has now placed another animal into the self-sharpening set, Schistocerca gregaria, the desert locust.

Ulrike G. K. Wegst, research associate professor of physics at Northeastern University, has discovered that locust exoskeletons build up concentrations of zinc in their mandibles, which hardens their “shovel-shaped mouthparts” — according to the research — in relation to the surrounding cuticle.

A locust’s exoskeleton is composed of chitin, a fibrous material not unlike the cellulose found in plants and common to both insects and marine life like crustaceans.

An animal’s chitin varies depending on use. In some parts of the body it needs flexibility — e.g., around jaws that need to open and close — and in others it needs significant hardness.