Compliance with environmental standards in facilities housing mice is generally the responsibility of:

• A. The principal investigator
• B. The animal care staff
• C. The maintenance staff
• D. The building manager

Answer: (B)

The main idea is that daily care and monitoring of the mice and their housing environment are carried out by the animal care staff. They perform the routine tasks that directly influence environmental standards: cleaning and sanitizing cages, changing bedding, feeding and watering on schedule, and maintaining proper waste disposal. They also routinely check and record room conditions such as temperature, humidity, ventilation, and light cycles, and they observe the animals for any signs of distress or illness, correcting issues according to standard operating procedures. This hands-on, ongoing work is what keeps the environment within required standards and ensures consistent husbandry.

The principal investigator bears overall responsibility for ensuring that the study complies with approved protocols and regulatory requirements, but day-to-day environmental compliance is carried out by the staff who work directly with the animals. Maintenance staff handle facility systems—like HVAC, plumbing, and electrical repairs—when problems arise, rather than managing routine environmental parameters. The building manager oversees broader facility operations and safety, but not the routine daily management of the mouse environment.