HAS TO BE AT LEAST 10 YEARS OLD TO BE ARRESTED AND FACE CHARGES. WE KNOW TO LOOK OUT FOR POISONOUS SNAKES BUT CATERPILLARS? ONE DANGEROUS SPECIES IS ON THE RISE. A STING FROM JUST ONE OF THEM SENT A MAN TO THE HOSPITAL. LOCAL 2'S SYAN JOINS US WITH MORE. Reporter: WELL, DOMINIQUE, BUG EXPERTS SAY THAT OUR WEATHER MAY HAVE LED TO A POPULATION EXPLOSION AMONG THESE POISONOUS CATERPILLARS THAT ARE NOW SUNDING MORE AND MORE -- SENDING MORE AND MORE PEOPLE TO THE HOSPITAL. PHILIP WAS TAKING OUT THE TRASH. AND TAKING HIS NORMAL SHORTCUT THROUGH THE BACKYARD BAMBOO. I NOTICED THAT MY KNUCKLE WAS HURTING. WALKED THROUGH HERE, AND THEN AS SOON AS I GOT INSIDE, I STARTED FEELING THE PAIN AND THEN I SAW THE -- THE BUG ON MY SHOULDER. Reporter: THE BUG WAS ACTUALLY THIS ASP CAT PILLAR. ASP IS WORST THAN ALL OF THEM. Reporter: THE CATERPILLAR'S FUR-LIKE COVERING IS CUTE AND CUDDLY, BUT IT'S POISONING AND PAINFUL -- POISONOUS AND PAINFUL, SOMETHING PHILLIP FOUND OUT FIRSTHAND. IT WAS A LIKE SHARP, VERY, VERY SHARP. AND YOU KNOW, IT JUST KEPT GETTING -- GROWING MORE AND MORE PAINFUL. IT STARTED HERE, AND THEN IT ENDED ALL THE WAY DOWN TO HERE. AND IT WENT TO MY ARMPIT. AND THAT'S WHEN I COLLAPSED. AND I CALLED MY DAD TO COME OVER AND TELL HIM TO TAKE ME TO THE EMERGENCY ROOM. Reporter: HE WAS HURTING SO BADLY, DOCTORS AT MEMORIAL HERMANN GAVE HIM MORPHINE AND PUT HIM ON AN I.V. ASP CAT PILLARS THRIVE IN ALL TYPES OF TREES AND SHREMEMBERRY. THIS ONE IS MAKING ITS WAY TOWARD HOUSTON AND MAYBE IT'S JUST FAVORABLE CONDITIONS. Reporter: AND FILLEP SAYS HE WON'T TAKE ANY MORE SHORTCUT OSTRASH DAY. I'M NOT GOING TO GO THROUGH THERE AGAIN UNLESS IT'S CUT DOWN. I DON'T WANT TO GET BIT AGAIN OR STUNG. Reporter: AND PHILLIPS SAYS NEARLY 24 HOURS AFTER HE WAS STUNG, HE IS STILL FEELING VERY SORE. ENTMAULINGS A -- EJ ENTOMOLOGISTS SAY THERE WILL LIKELY BE MORE ENCOUNTERS WITH THIS CATERPILLAR BECAUSE THEY'LL BE HERE UNTIL FALL. WEAR LONG SLEEVES AND PANT PHYSICAL YOU'RE OUTSIDE. BUT -- PANTS IF YOU'RE OUTSIDE. BUT USE TAPE TO REMOVE THE SPINE