Whichever way you look at it life for a rodent is brutal. I have three sticky traps set around the garage. If I ever caught one chewing on my car wiring I would have no trouble killing it with whatever was handy.
A few years ago my daughter was doing animal research and had to euthanize mice.
They were frozen and their brains sliced so they could be studied under a microscope.
I don't know where she got the drive to do that to further her career. She managed.
I don't know what the purpose of rodents is in this world but I am sure a biologist would have a good explanation. Now killing a deer with a bow and arrow I would be more sensitive about.
