They are actually pretty small. They are about a few inches. They are the common species that get in your house here in the AZ desert. They are tan/beige and blend in really well to carpet/tile so it is easy to almost pick one up or step on them. They can climb walls, hang on your ceiling and fall in your bed. etc. The barks are the dangerous species with potent venom that can cause problems if you are stung. The pain is said to be excruciating and long lasting and can cause nasty symptoms. A friend of mine had a pretty bad reaction to a sting. I find a couple in the house every summer. Luckily we don't get an infestation like some people. I did see a giant hairy desert scorpion once! It was quite a site.