</font><font color="blue" class="small">( Some snake trivia. A poisonous snake will have slit pupils like a cat and a nonpoisonous snake will have round pupils like a human. As for myself, I don't want to get close enough to see the difference. )</font>
That is true for most North American venomous snakes. All of the pit vipers have vertical slits for pupils. The coral snake, however, isn't a pit viper (it's more closely related to cobras) and has round pupils.
We also have other venomous snakes that aren't considered harmful to humans. The hognosed snake is an example. Hognosed snakes have a mild venom and their rearfanged, so they'd literally have to "chew" on you to envenomate you. Rather than bite, they're more likely to pretend to be a cobra by flattening their head/neck and hissing loudly (they're sometimes called "spreading adders"). If this doesn't scare you away, they'll flop their mouth open, roll over on their back, and play dead. When in this stage of their "show" you can roll them back over on their bellies and they'll quickly flip back onto their backs. I recon they think dead snakes should be on their back. /forums/images/graemlins/laugh.gif
BR