Nature’s weirdest kitchen gadget: The lobster’s stomach ‘teeth’

2 min readNew DelhiJul 25, 2026 11:00 AM Most of us think chewing happens in the mouth. After all, that’s where our teeth are. Well, that’s not the case with lobsters who seem to have a shocking way of chewing.
These armoured crustaceans don’t actually chew with their mouths. Instead, they have a set of tooth-like structures inside their stomach that grind up food after it is swallowed.
The unusual mechanism is called a gastric mill. Located in the lobster’s foregut, it conss of three hard, tooth-like plates made from chitin — the same tough material that forms the animal’s shell.
When a lobster eats, its mouthparts help tear and move food into the digestive system. The food then reaches the gastric mill, where the stomach “teeth” crush and grind it into smaller pieces before digestion continues. Scients often compare the gastric mill to a tiny internal food processor.

Why did lobsters evolve such a strange system?

One reason is that their mouthparts are already busy handling, tearing and manipulating food. Moving the grinding process deeper into the digestive tract allows them to process a wide variety of meals, from fish and molluscs to algae and decaying organic matter.
Interestingly, lobsters are not the only creatures with this adaptation. Many crustaceans, including crabs and crayfish, possess similar stomach-based grinding structures.
The teeth themselves wear down over time, but lobsters have a clever solution. Because they periodically shed their exoskeleton in a process known as moulting, they also replace parts of their gastric mill, effectively growing new stomach teeth.
The next time you see a lobster on a nature documentary or a restaurant menu, remember: its most important teeth aren’t in its mouth at all. They’re hidden inside its stomach!