Brown recluse spiders have been feared since they were discovered in 1940, and people will often take drastic approaches to rid their homes of these spiders. Spider experts noticed that the bite of a brown recluse could sometimes lead to a terrible infection called necrosis. Sometimes the necrosis becomes fatal, but these fatal bites are actually very rare, and most bites from brown recluses are no more harmful than a normal spider bite. The spider's bite is most dangerous for people who are young or overweight.