How many rats can live in one burrow? - briefly
A standard burrow usually holds two to six rats, with capacity varying by tunnel dimensions and social hierarchy. Larger, more complex tunnel networks can support up to about a dozen individuals.
How many rats can live in one burrow? - in detail
The capacity of a single rat burrow depends on the species, burrow architecture, and environmental conditions. A typical brown rat (Rattus norvegicus) creates a tunnel system ranging from 0.5 m to 1.5 m in length and 10–15 cm in diameter. Within this space, an adult occupies roughly 0.02 m³, leaving room for nesting material and movement.
Observed occupancy patterns show:
- Standard family groups: 2–4 adults plus 5–12 juveniles; total 7–16 individuals.
- High‑density colonies: up to 30 rats in a complex network of interconnected chambers, recorded in urban sewers and agricultural waste piles.
- Maximum experimental load: 45 individuals forced into a 1 m³ artificial burrow, resulting in severe stress and mortality within 48 hours.
Key variables influencing the number of occupants:
- Burrow size and depth – larger, multi‑level systems support more rats.
- Soil composition – loose, well‑drained substrates allow easier expansion.
- Food availability – constant supply permits higher densities; scarcity reduces occupancy.
- Temperature and humidity – moderate climate reduces thermoregulatory stress, allowing tighter packing.
- Health status – disease outbreaks limit sustainable numbers.
In practice, a functional burrow in a natural setting typically houses 10–20 rats. Exceeding this range leads to competition for resources, increased aggression, and higher mortality, making the colony unstable.