Both snakes were found less than a 1/4 mile from our classroom. The rattlesnake was dead when I found it. I brought it to the kids because we frequently see bull snakes (not venomous). In a still photo, these two are easy to distinguish, but in real life, slithering through brush and rocks, it's not easy to tell who's who.
This is only the second rattlesnake I've seen in Taos County, and I'm outside in their territory a lot. So, I don't fear them. But I'm not reckless either. We talk frequently about snakes and the kids know to back away if they see one.
I brought the snake because I wanted the kids to have a chance to identify it with their own eyes (did the same with a black widow once). Note the big head on the rattler. This one is just a baby, so its rattle is hardly noticeable. In a pinch, I'd look for the head. The markings are too similar and you often can't find the tail.
Plus, now the kids get to tell everyone they carried a rattlesnake around (even if it was dead).