LOLOLOL at will!!
Oh man, I've always wondered if snakes have the capability to get high, I've just always thought it was too much of a crackpot idea to post! That and I keep forgetting to look it up the next morning ;) Kidding!
I don't know much of anything about reptile biology compared to mammals, but I'm assuming that THC would have some sort of an effect if they have the right receptors in their brains. Considering how simple their bodies are, they probably don't even have a blood-brain barrier, so you could risk totally perma-frying an animal if it does affect them. One hit for a human blown into the cage would be like a roomful of smoke for them.
Update: a google search shows that some random guy states that "reptiles lack a blood-brain barrier" but I dunno about the validity. Also, I'm not a biology major (yet) so I could be waaaay off.