Most of us get a little excited when we see a big spider, but for the unfortunate few who fall victim to the bite of the daunting Brazilian wandering spider, that “excitement” takes on a whole new meaning: The venom of the wandering spider — also known as the banana spider (or more formally Phoneutria nigriventer) causes erections in men.
“The venom of the P. nigriventer spider is a very rich mixture of several molecules,” says Dr. Kenia Nunes, a physiologist at the Medical College of Georgia who is currently studying the odd side effect. “These molecules are called toxins, and then we have various toxins in this venom with different activity. Because of this, when a human is bitten by this spider, we can observe many different symptoms including priapism, a condition in which the penis is continually erect.”
In addition to the hours-long painful erection, the wandering spider’s bite can cause loss of muscle control, severe pain, difficulty breathing and, if not treated, death, due to oxygen deprivation (with anti-venom, the victim usually recovers within a week.)