ZEPHYRHILLS ó The Pergolasí Saturday morning volunteer work started like most, at a farm cleaning the property and trimming trees. Andrea Pergola, 38, stood on the driveway of the property when she heard her 15-year-old son Logan scream. At first, she thought he was injured by a chainsaw. Logan has a high pain tolerance, so she knew whatever happened must have been bad. "Buddy, what happened?" she asked. "I got stung!" Logan shouted. Pergola looked at Loganís arm and saw a massive welt beginning to form. The pattern on his skin reminded her of an alien, she said. The culprit was a southern flannel moth larva, known as a puss caterpillar. The caterpillars are common in most parts of Florida, said Lyle Buss, senior biological scientist at the University of Florida. Stinging spines on the caterpillarís body can inject venom into anyone who rubs against it. Most stings are harmless, only producing a rash. But for Logan, the reaction was more severe. Now, Pergola has shared her sonís experience on Facebook, hoping to protect others, especially younger children, from the pain Logan went through. After the initial sting, Loganís hand went numb, but his arm felt like it was on fire. "Help me!" he screamed as his mom tried to help. "Letís take a breath and rinse it off," she said. She ran his arm under cold water, but Loganís eyes started glazing over and he wasnít focusing. He started feeling dizzy. Thatís when Pergola knew she needed to get her son to the emergency room. "My mom instinct just kind of kicked in," she said. "I knew I needed to stay calm and keep him calm." Before she took him to the hospital, she gathered her family and prayed for Logan, asking God to protect him and not let the sting inflict any permanent damage. She loaded up her truck with her mom, Logan and the caterpillar that she collected and put in a plastic bag to show the doctor. Logan could feel the pain moving through his bones. He started having tremors. The doctor knew exactly what it was and assured Logan the pain would subside. With medication and an IV, the pain at least became manageable, Pergola said. The next day, he had a little bit of pain, and by Monday, he was completely fine. He still has slight red markings that will be on his arm for a few weeks. While they were in the hospital, family members kept reaching out, asking if everything was okay. Pergola decided to post on Facebook to let other people know that her son was fine and to warn others about the caterpillar. She had no idea her cautionary tale would become as big as it did, having around 66,000 reactions and 407,000 shares as of Wednesday afternoon. "I donít think Iíve ever posted a BE AWARE post before- but after today I think this is super important," she wrote. She said one of her biggest motivations for making the post public was so that other people could watch out for these caterpillars. Although the caterpillars are common in the state of Florida, Pergola, whoís lived in Pasco County her whole life, has never seen one. "You need to be careful," Pergola said. "I want to let people locally around us be aware." Puss caterpillars mostly feed on oak trees, Buss said. Theyíre not the only stinging caterpillar in Florida, but they are the worst. In general, itís a good idea to avoid any hairy caterpillars you come across, Buss said. "If you do see one, leaving them alone is the best thing to do," Buss said.