A mouth built around a pair of digging tools
A naked mole-rat’s protruding incisors are not simply an odd-looking feature. They let the animal bite into compact soil while keeping its mouth protected from the material it is breaking apart. The lips meet behind the teeth, forming a seal around the mouth even as the incisors remain exposed.
That arrangement matters because burrowing means working face-first in loose earth. Without the seal, soil could be pushed into the mouth with each bite, interfering with breathing or swallowing. Instead, the teeth meet the ground directly, and the rest of the mouth stays sheltered behind them.
Teeth do the cutting; the body moves the earth
The incisors act like small chisels: repeated bites break up soil at the tunnel’s edge. The animal can then shift loosened earth out of the way as it advances. In this setup, the teeth are the leading edge of the burrowing animal, not just tools for eating.
The design also helps explain why naked mole-rats can keep digging in confined tunnels. Their lips do not need to open wide around each bite, so the mouth can remain sealed while the incisors work. A simple change in where the lips close turns exposed teeth into a practical excavation tool—and keeps the soil on the outside of the animal.
