With the exception of two small spider families that don’t possess venom glands, all spiders are technically venomous, but not all spiders are capable of biting humans. This is because some spider species possess fangs that are too small to puncture human skin. And since spiders did not evolve venom to subdue humans, the vast majority of spider species produce venom that would have no ill effects on the human nervous system.

Of the 50,000 or so spider species that have been documented around the world, there only exists 25 species that can inflict medically significant venomous bites to humans. The abundance and diversity of venomous spider species obviously varies by region, but in any given area, a person can expect to find between 0 and, at most, 3 venomous spider species.

The United States is home to around 3,000 spider species, only two of which, the brown recluse and the black widow, are considered “medically significant” spider species. However, around 80 percent of all hospitalizations that result from spider bites involve bite victims who had a serious allergic reaction to venom. Unfortunately, the state of Louisiana is home to several potentially dangerous spider species that are often spotted in homes.

The most venomous spider species in the US, the black widow, is found in Louisiana, but this species does not enter homes often, and most bites are sustained while outdoors. The non-native brown widow, on the other hand, is being found more and more within Louisiana homes, but this species produces venom that is less potent than black widow venom. Yellow sac spiders may be responsible for the greatest amount of problematic indoor spider bites. Although sac spider bites are painful, and bite wounds can take weeks to heal, their bites are never fatal.

Several jumping spider species can be found in Louisiana including the twin-flagged jumping spider. This species inflicts painful bites and they are found in Louisiana homes frequently. Bites from this species are never fatal but allergic reactions to their venom can send some bite victims to the hospital. The brown recluse is also found inhabiting cluttered areas of a home that are not often frequented by humans. These areas include garages, attics and storage areas. These spiders are shy, but their bites can cause necrotic lesions that require medical attention.

Have you ever sustained a bite from a spider that you did not recognize as a particular species?