Most spiders are harmless. Yes, they’re insanely creepy (nothing should have THAT many legs), but almost every spider you’ll see in the US will do you no harm.

However, there are some spiders that are a little more dangerous. If you see them, steer clear! Here are the most dangerous arachnids in America:

1. The brown recluse

Most people have heard of this spider. It tends to have a body that’s less than an inch long and has a mark shaped like a dark violin that points toward its abdomen. If one bites you, you can experience serious injury and should get to a doctor right away. You’ll find these guys in the south.

2. The black widow

Another well-known spider, the Black Widow is black and shiny, with an orange or red mark on its stomach that can look like an hourglass or a dot. They tend to hang out in sheds, garages, messy basements, in between stones, and in piles of rubble. The venom can cause horrible pain, nausea, and other unpleasant symptoms, including possible death.

3. The tarantula

These guys can be large, hairy, and thick. You probably won’t find them outside of 12 specific states, but just knowing they’re out there is enough to make a person’s skin crawl. All are poisonous, but there is no record of a bite ever proving deadly. They do, however, tend to be excruciating.

4. The wolf spider

These guys can get pretty big, and they have a brown/gray speckled color, plus a marking on the stomach that looks like a Union Jack. They move quickly and have a painful, venomous bite that’s unpleasant but not deadly. Thankfully, they won’t bite unless they feel threatened.

5. The hobo spider

This large spider is brownish in color, with chevron-shaped markings on its abdomen. They live in Oregon, Washington, Wyoming, Montana, Colorado, Idaho, and Utah. Bites lead to a disgusting, painful blister, typically accompanied by a headache, weakness, nausea, fatigue, short-term memory loss, and damaged eyesight.

6. The red widow

This creepy crawly has a black abdomen with red and yellow spots, with the rest of its body colored an orange red. You can find it in central and southeast Florida, usually in shrubs. The female spiders bite, and their neurotoxic venom can cause muscle spasms.

If you see a spider (in general), it’s best not to aggravate it. And if one bites you, seek medical attention. Again, most US spiders are no threat to humans, so chances are you will be fine! The worst thing a person can do in this situation is panic.