What do mice and rats not gnaw? - briefly
Mice and rats typically avoid gnawing metal surfaces or glass, because these materials are too hard to chew.
What do mice and rats not gnaw? - in detail
Rodents possess continuously growing incisors that compel them to bite and wear down a wide range of substances. Their chewing activity is limited by material hardness, chemical composition, and palatability. Items that remain untouched include:
- «metal» alloys such as steel, aluminum and copper; their tensile strength exceeds the bite force of the incisors.
- «glass» and other vitreous materials; brittleness prevents effective gnawing and results in immediate fracture rather than abrasion.
- «ceramic» tiles and porcelain; crystalline structure resists deformation and causes rapid wear of teeth.
- «stone» and concrete; high compressive strength and lack of edible nutrients deter gnawing.
- Certain high‑density polymers, for example polycarbonate and some acrylics; molecular rigidity limits cutting ability.
- Toxic or unpalatable substances, including strong acids, alkalis, and some insecticides; chemical deterrents inhibit chewing behavior.
In addition, live prey larger than the rodents themselves, such as adult insects or small vertebrates, are not typically gnawed; the animals capture and consume them whole or kill them through other means.
The avoidance of these materials protects the rodents’ incisors from premature wear and prevents ingestion of harmful chemicals. Consequently, environments containing predominantly hard, inert, or toxic objects experience reduced damage from rodent activity.