The only way to be sure that a bite came from a brown recluse spider is to see the spider bite you, capture it, and then definitively identify its type.
Most don’t even get the chance. Many people don’t even realize they’ve been bitten at first. It’s even rarer for a person to see the spider bite them and be able to catch it before it scurries off.
If you’re lucky enough to see the spider, look for these telltale traits:
- Six eyes: These are set in pairs called dyads. One dyad will be up front and the other two will be on either side of the head. This is the most reliable marker of a brown recluse, as most other types of spiders have eight eyes.
- Furry abdomen: The abdomen is the larger section of the body. On a brown recluse it will have fine hairs and be a solid color.
- Legs: These are one solid, light color.
- Body length: Without the legs, this spider is no more than 3/8-inch long.
Brown recluses are also called violin spiders or fiddlebacks. These names refer to a violin-shaped mark on the spider’s back. This marking is not always obvious on brown recluses. The pattern appears on other species as well.
All of that said, identifying a brown recluse is difficult even for spider experts and doctors. Whether you think you’ve been bitten by a brown recluse or you’re unsure, seek medical attention if you notice a bite getting worse.