How does a rat gnaw through walls? - briefly
Rats employ continuously growing incisors that self‑sharpen as they gnaw, combined with powerful jaw muscles that produce rapid, repetitive bites, allowing them to cut through wood, plaster, drywall and similar building materials. Their ability to grind material into fine particles and discard it enables them to breach walls efficiently.
How does a rat gnaw through walls? - in detail
Rats possess incisors that grow continuously throughout life. The enamel on the front edge is exceptionally hard, while the dentin behind it wears away, maintaining a sharp cutting edge. Strong masseter and temporalis muscles generate bite forces sufficient to concentrate pressure on a tiny surface area, allowing the teeth to slice through soft and semi‑hard building materials.
When a rat encounters a barrier, it follows a predictable sequence:
- Assessment: The animal taps the surface with its whiskers and forepaws to gauge resistance.
- Initial breach: Using the front incisors, it creates a small puncture or gouge, often no larger than a few millimeters in diameter.
- Expansion: Repeated strokes enlarge the opening. The rodent alternates biting and pulling, using its forelimbs to steady the head and apply additional torque.
- Progression: Saliva, rich in enzymes, moistens the material, reducing friction and aiding chip removal. The rat discards debris with its paws.
Material susceptibility varies:
- Drywall and plaster: Low tensile strength; rats can penetrate within hours of persistent gnawing.
- Softwood framing: Fibrous structure yields to repeated incisions; rats may hollow out channels for nesting.
- Concrete and brick: High compressive strength slows progress; rats exploit mortar joints, cracks, or pre‑existing gaps, gradually widening them.
- Metal sheeting: Only thin, unreinforced sheets are vulnerable; rats may gnaw through seams or perforations.
The bite force of a common Norway rat (Rattus norvegicus) averages 0.5 N per tooth, but the cumulative effect of rapid, high‑frequency strokes (up to 150 bites per minute) produces sufficient energy to displace material particles. Continuous tooth growth ensures that wear does not diminish cutting efficiency, allowing the animal to maintain pressure over extended periods.
The resulting damage typically appears as circular or oval openings with smooth edges, surrounded by chewed fibers and shredded insulation. Identifying these signatures helps locate entry points for exclusion measures.