Which statement best describes enrichment for laboratory mice?

• A. Enrichment should be edible only.
• B. Enrichment is optional and can be any object regardless of safety.
• C. Nesting material, shelter, tunnels, and chewable items should be provided and be safe, clean, and non-interfering with procedures.
• D. Enrichment must always be removed before procedures.

Answer: (C)

Enrichment for laboratory mice means providing a range of safe, non-interfering items that support natural behaviors, such as nesting material, shelter, tunnels, and chewable items. These should be clean and safe to prevent harm or interference with procedures or data collection. This is the best description because it covers multiple types of enrichment, emphasizes safety, and recognizes that enrichment should not be limited to edible items or treated as optional, nor does it require removal before every procedure. In practice, enrichment is provided to improve welfare, with temporary adjustments only if a specific procedure or protocol necessitates removing certain items.