It honestly looks like something you’d want to pet. The puss caterpillar is small, fuzzy, and kind of adorable — like a little hairy teardrop. That’s exactly the problem.
Hiding beneath all that soft, cat-like fur are toxic spines that can embed in your skin and cause intense pain that can last for hours — and in some cases, days or even weeks. You won’t see the spines coming. You’ll just feel them — immediately, and badly.
The spines themselves are hollow, with a toxin gland sitting at the base. And here’s the part that catches people off guard: the bigger the caterpillar, the more toxic the sting. So a larger one isn’t just scarier-looking — it’s actually more dangerous.
Reactions can go beyond pain at the sting site. We’re talking vomiting, swelling, and in some cases, serious enough reactions that people end up in the emergency room. Severity varies from person to person, so don’t assume a sting is no big deal just because someone else shrugged one off. These caterpillars live across the southern United States, so if you’re in that region and you spot something weirdly fluffy on a tree or shrub, don’t touch it.
Same goes for other stinging caterpillars — the saddleback, io moth, buck moth, and slug caterpillars can all cause problems. Note: the puss caterpillar is itself the larval stage of a flannel moth, so those are the same creature at different life stages. The rule is simple: if a caterpillar looks unusual, leave it alone. Cute in nature doesn’t mean safe.