Where should a rat be placed? - briefly
Place the rat in a secure, well‑ventilated cage that offers sufficient floor space, appropriate bedding, and enrichment items such as tunnels and chew toys.
Where should a rat be placed? - in detail
Placement of a rat must consider welfare, experimental integrity, and safety. The animal requires a stable environment that supports natural behavior while minimizing stressors that could affect physiological measurements.
A suitable enclosure should provide at least 0.5 m² floor space per adult rat, with solid flooring covered by absorbent bedding. Enrichment items—such as nesting material, chew blocks, and tunnels—must be included to promote exploration and reduce stereotypies. Ventilation should ensure fresh air exchange without creating drafts, and temperature must be maintained between 20 °C and 26 °C with relative humidity of 40‑70 %.
Location within the laboratory influences external variables. The cage should be situated away from high‑traffic zones, loud equipment, and direct sunlight. Lighting cycles need to follow a consistent 12‑hour light/12‑hour dark schedule, with illumination levels not exceeding 300 lux during the light phase. Noise levels should remain below 55 dB to prevent auditory stress.
Safety measures include secure cage lids, lockable racks, and barriers that prevent accidental escape. Surfaces surrounding the cage must be easy to clean and disinfect, reducing pathogen transmission. Waste removal systems should operate without exposing the animal to handling disturbances.
Practical recommendations:
- Use individually ventilated cages (IVCs) or sealed racks with HEPA filtration.
- Position cages on stable shelves at a height that allows easy observation without bending.
- Arrange cages in rows with at least 15 cm spacing to facilitate cleaning and airflow.
- Monitor temperature and humidity with calibrated sensors placed near the cage level.
- Implement a regular schedule for cage cleaning, bedding replacement, and enrichment rotation.
Adhering to these guidelines ensures that the rat occupies an environment conducive to health, reliable data collection, and compliance with ethical standards.