I'm not sure where this belongs, and it's not a big deal, it's a question about a very minor problem. Snowball is a very healthy and contented cat, but he has never seemed to purr very well. If we gently put our fingers on Snowball's throat, we can feel vibrating, or if Snowball is in someone's lap we can feel his entire body vibrating. If he actually purrs loud enough to be heard, it fades after a second or two and he goes back to just vibrating. I don't know of any other cats that do this and I was just wondering if anyone had any information about this behavior?