I’m pretty sure most cat owners already know this. I learned it on my Grandpa’s farm. Pick up a cat by the scruff, and they get real calm. It’s a kitten behavior, designed for when mama cat carries you around. It works on adult cats (usually), but I sort of hold their butts up too since an adult cat is a lot heavier than a kitten and I’m not sure it’s safe to carry one just by the scruff.