If you are not from the south, you may have only heard about fire ants. These ants make a distinctive looking mound – that you don't always see in time. Here's one at the base of a big rock in my front yard.
If you poke the mound, thousands of tiny ants flood out. If you aren't paying attention, they climb up your leg and then they all bite you at once. It feels like fire, hence the name "fire ants". I took a stick and drew across the bed…
… I hope you can see the fire ants. I moved away pretty quickly.
Click on the picture and I think a bigger one will open for you. The little white ovals are eggs. You can see the ants better on the rock. I have at least 3 of these fire ant beds out front and I have to watch my grandkids so that they don't get into them.