Which of the following is an example of species-appropriate enrichment for mice?

• A. A large water bottle.
• B. Bright flashing lights.
• C. A loud mechanical noise cage.
• D. Nest materials and hiding spaces.

Answer: (D)

Enrichment for mice should enable natural behaviors like nest-building and seeking shelter, which supports their welfare by reducing stress and promoting exploration. Nest materials and hiding spaces let mice create secure microhabitats, regulate temperature, and engage in repetitive, species-typical activities that are comforting and mentally stimulating. A larger water bottle is mainly a hydration resource, not an environment feature that encourages natural behavior. Bright flashing lights disrupt the mice’s circadian rhythms and can be stressful, and a loud mechanical noise cage adds aversive stimuli rather than opportunities for positive interaction. Therefore, providing nest materials and hiding spaces best aligns with what mice need to express their natural behaviors and stay comfortable in captivity.