The Best Bedding For Mice & Rats
Introduction
The bedding you choose for your pets plays a major role in their overall health and behavior. In this article, I’ll break down the best bedding options for mice and rats based on research as well as my own experience as a mouse fancier.
Wood‑Based vs. Paper‑Based Bedding
Wood and paper bedding are the most commonly used substrates in both pet and laboratory settings. To keep things simple, I’ll focus on the three most popular types: pine shavings, aspen shavings, and paper bedding.
Paper Bedding
Paper bedding (such as CareFresh or Kaytee) is soft, comfortable, and excellent for burrowing. However, it is also very dusty and tends to trap moisture and ammonia. Because mice and rats produce high levels of ammonia in their urine, this trapped ammonia can quickly irritate and damage their respiratory systems.
Even with frequent cleaning, ammonia buildup can be difficult to control. For example, when I tested Kaytee Clean & Fresh with a single mouse, the bedding became damp within three days. By day five, mold had developed in the bedding and along the enclosure walls due to how much moisture the substrate retained. The mouse was removed on day three for safety, yet the bedding still failed to dry out properly. The enclosure contained only plastic enrichment to avoid additional moisture retention.
This aligns with research showing that paper bedding can reach high ammonia concentrations in as little as two weeks.
Wood Bedding
Wood-based bedding—typically pine or aspen—is a more reliable option. Pine shavings are soft, while aspen tends to be coarser. Both hold burrows reasonably well, though not quite as effectively as paper.
Dust levels vary: pine is slightly dustier than aspen, but still far less dusty than paper bedding.
Most importantly, both pine and aspen are effective at absorbing and neutralizing ammonia, making them much safer for small animals. Aspen is generally more absorbent than pine, but both perform well in typical pet setups.
Alternative Bedding Options
Other substrates—such as newspaper, pellets, coconut coir, and fleece—come with limitations.
- Fleece can be used safely in hammocks or hanging hides but should not be used as the main substrate. It requires strict, frequent cleaning to prevent odor and bacterial growth.
- Coconut coir and pellet bedding can be offered in dig boxes for enrichment but should be cleaned or replaced regularly.
- Newspaper is not recommended as a primary bedding due to poor absorbency and limited odor control.
Conclusion
For mice and rats, the most reliable and health‑conscious bedding choices are wood‑based substrates such as kiln‑dried pine, aspen, or hemp. These materials manage ammonia effectively, support natural behaviors, and maintain a healthier environment overall.
Paper bedding (and newspaper) should be avoided as a main substrate. While small amounts can be offered as nesting material, it is not suitable for full‑cage use due to moisture retention and ammonia buildup.
