 More often than not, it's a simple garter snake. While some parts of the country do have venomous snakes to beware of, the common garter snake is no threat to humans. Here's a few reassuring garter snake facts. They're quite shy and won't bite unless provoked. If you should be bitten, the worst you can expect is a slight swelling or rash. And best of all, garter snakes have a healthy appetite for slugs, cucumber beetles, squash bugs, oh, and mice, too.