The insects are sometimes called puss caterpillars because of their resemblance to fluffy cats, according to University of Florida entomologist Don Hall.
"A puss caterpillar sting feels like a bee sting, only worse. The pain immediately and rapidly gets worse after being stung, and can even make your bones hurt," Hall told National Geographic. "How bad the sting hurts depends on where you get stung and how many spines are embedded in your skin. People who have been stung on the hand say the pain can radiate up to their shoulder and last for up to 12 hours."
The caterpillars, which prefer hanging out in oak, oleander and plum trees, are active July through November, according to KVUE.
The caterpillar embeds its venomous spines into the skin and can cause burning pain, swelling, nausea and itching, KVUE reported.