Dylan is a MC mix and he can react in this way, which is so surprising because overall he is a gentle laid back goon. Catnip is almost too stimulating for him - he does not get mean, but gets wired and will playbite and smack his siblings.
I have also learned NEVER to touch his belly unless he has it fully exposed. If he is belly up, I can bury my face in that belly, smooch away as much as I want. But if he is laying any other way - DO NOT TOUCH BELLY!