Which practice best supports reducing stress during routine handling of mice?

• A. Gentle two-handed restraint with proper support.
• B. Grasping the mouse by the tail alone.
• C. Handling while under warm light stress.
• D. Restraint with a chemical immobilization.

Answer: (A)

Gentle, non-aversive handling with a two-handed restraint and proper support reduces stress by giving the mouse a sense of security and allowing controlled, calm movement. When one hand cups and supports the body (often around the thorax and hindquarters) while the other provides gentle restraint, the animal isn’t pulled by the tail or forced into awkward positions. This setup minimizes sudden struggles, maintains breathing, and reduces the fear response, making routine tasks like weighing, checking, or transferring safer and more predictable for both mouse and handler.

Grabbing the tail alone is abrupt and signals a threat, which elevates stress and can lead to struggling and potential injury. Handling under a bright or warm light can add discomfort or glare, and chemical immobilization is invasive and introduces additional stress, not appropriate for routine handling. Emphasizing calm, supported restraint supports welfare and improves the reliability of routine care and measurements.