How many rats can be kept in a single cage? - briefly
A single cage generally accommodates up to two adult rats, providing at least 450 square inches of floor space per animal. Exceeding this limit compromises welfare and increases disease risk.
How many rats can be kept in a single cage? - in detail
The capacity of a cage for laboratory or pet rats depends on cage size, floor space, and the age or size of the animals. Regulatory agencies and best‑practice guidelines provide specific minimum floor‑area requirements:
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Standard laboratory cages (plastic, solid bottom):
- Adult rats: at least 0.06 m² (≈ 600 cm²) per animal.
- Juvenile rats: at least 0.04 m² (≈ 400 cm²) per animal.
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Large‑scale breeding cages (metal, wire‑mesh floor):
- Adult rats: minimum 0.08 m² (≈ 800 cm²) per animal.
- Juveniles: minimum 0.05 m² (≈ 500 cm²) per animal.
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Home‑cage setups for pet owners:
- Minimum recommendation: 0.07 m² (≈ 700 cm²) per adult; larger cages improve welfare.
To translate these figures into a practical count, calculate the usable floor area of the cage and divide by the appropriate per‑rat requirement. Example calculations:
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Cage measuring 40 cm × 60 cm (0.24 m²):
- Adult capacity = 0.24 m² ÷ 0.06 m² ≈ 4 rats.
- Juvenile capacity = 0.24 m² ÷ 0.04 m² ≈ 6 rats.
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Cage measuring 50 cm × 80 cm (0.40 m²):
- Adult capacity = 0.40 m² ÷ 0.06 m² ≈ 6–7 rats.
- Juvenile capacity = 0.40 m² ÷ 0.04 m² ≈ 10 rats.
Additional considerations:
- Enrichment and nesting material reduce usable floor space; subtract roughly 10 % when estimating capacity.
- Social hierarchy may cause dominant individuals to monopolize space; monitor behavior and adjust numbers if aggression appears.
- Health monitoring requires enough space for routine cleaning, inspection, and isolation of sick animals.
In practice, most facilities limit groups to 4–5 adult rats per standard cage to allow for enrichment, ease of handling, and compliance with welfare standards. Larger cages may accommodate up to 8 adults, provided that ventilation, bedding, and enrichment remain adequate.