All of the following are practical methods of identifying mice EXCEPT:

• A. Leg band
• B. Ear tag
• C. Microchip
• D. Cage card

Answer: (A)

The way researchers identify mice focuses on options that are safe, durable, and easy to read. For individual identification, ear tagging or microchips are commonly used because they stay with the animal and can be read without excessive stress. Cage cards provide identification at the cage level, helping staff know what group or strain is housed there. A leg band isn’t practical for mice because their small legs make a band unsafe and easy to slip off, potentially causing injury or restricting movement. It’s also hard to keep readable on such a tiny limb. So, leg bands are the method that wouldn’t be used, while ear tags, microchips, and cage cards are the workable options.