Summer brings more perils beyond sun burn. Wyatt McCaskill, 7, discovered that the hard way when he was playing in his front yard in Horn Lake, Missouri last August. He picked up a cute, furry caterpillar – and suffered immediate pain. That pain spread from his hand to his chest in minutes, and his terrified mother, Kelli McCaskill, rushed him to the hospital.

The furry caterpillar is the larval form of the Southern Flannel Moth (Megalopyge opercularis), which is native to the southeastern United States and ranges from North Carolina to Florida. It also occurs in Mexico and parts of Central America. The caterpillar, which is variously known as the puss moth caterpillar, Trump caterpillar, and asp has the nasty distinction of being one of the most venomous caterpillars in North America. Its sting is at least as painful as that of a bee or scorpion. It generally lives in trees and is most active from July to November.

It’s called the puss moth caterpillar because its long setae look like the fur of a Persian cat. That “fur” contains venomous spines that can break off and poison a person on contact. The venom can cause intense throbbing pain within minutes. Sometimes that pain remains localized; other times it radiates to other parts of the body. Other symptoms of envenomation include swelling, acute abdominal pain, nausea, vomiting, swelling and trouble breathing.

If somebody gets stung by a puss moth caterpillar, doctors advise using tape to remove the spines. The patient should then wash with soap and water and then use an ice pack to numb the pain. If the pain gets worse or the patient starts having trouble breathing, they should go to a doctor or hospital.