My ex worked at a medical research school for a while - part of her job was snapping the necks of test mice. They do it that way because it's the most humane (a

My ex worked at a medical research school for a while - part of her job was snapping the necks of test mice. They do it that way because it's the most humane (as in, quick and painless) way. Killing thousands of mice did have a non-zero impact on her emotionally.