My 6 yr old cat scruffs my 9 week old kitten every time she irritates him. He holds her by the scruff while hunching over top of her. She cries every time, but once he releases her, she comes right back at him. He even dragged her across the floor by the scruff one time. In over 40 years of owning cats, this is the first time I have seen this behaviour. I couldn't post this on my phone, but will try to post the video in the responses to this post so you can see what I mean.