Why does my Bengal cat scratch himself so badly?

It's part of the breed, or at least can be. My first Bengal kept pulling hair out until he had a bald spot an inch in diameter. (Yes, the skin is also spotted.) The hair would grow back fine, but he would find a new spot to pull at. In desperation, I boarded him at the vet's for a month, hoping for a cure. The vet found nothing, despite doing skin scrapings and tests. I finally came to the conclusion that he was somewhat neurotic. He was fine in all other areas, so he and I lived with it. I have since seen the same thing at a breeder's cattery. So I concluded that it is fairly common. Wish I could have given you better news. A very mold tranquilizer might help, but I wouldn't think that would be a solution for long term. Good luck.