Some help from a reader:

JG, Don’t worry. Here’s how you tell if the thing’s dangerous: The next time you see a snake and aren’t sure, pick it up and look it in the eye. If the pupil is round, it’s non-poisonous. If it’s diamond-shaped, put the snake down and back away slowly. (The same holds true for identifying alligators vs. crocs, btw.) Glad to help,