I never really think of moths or caterpillars as being venomous. I’m not afraid of them, and I used to always pick up caterpillars as a kid. I think I even had a tupperware container with branches and leaves that I would keep caterpillars in. But apparently there are some species of these cute animals that are venomous, so be wary of them!

One species of venomous caterpillar is the puss caterpillar, which can be found in the southern US, Mexico, and in Central America. The adults are known by multiple names, including puss moth and southern flannel moth, but I will refer to them as puss moths since that’s what the larvae are generally known as, and they are the interesting facet of this species. They prefer to live on trees, usually oaks, elms and citrus trees. These nasty critters can also be found on rose bushes and ivy.

The adult puss moth. So very fuzzy.  Image credit: Patrick Coin via Wikipedia
The adult puss moth. So very fuzzy.
Image by Patrick Coin (Patrick Coin), CC BY-SA 2.5, via Wikimedia Commons

Despite the fact that they are venomous, puss caterpillars and moths are actually pretty cute. The caterpillars are covered in long silky ‘hairs’ that make them look a bit like tribbles. Colour of the caterpillars ranges from grey-white to brown to dark grey. Often caterpillars have an orange stripe running down the top of their bodies. The moths of this species are still very fuzzy, with hair all over their body and legs, and black fur on their feet.

Puss moths are not dangerous to people, but the caterpillars definitely are. The tricky thing about these guys is that they look soft and fluffy, which makes people want to pet them. This is a mistake, don’t do it. Hidden inside that floofy ‘fur’ are venomous spines that get stuck in human skin and cause extremely painful stings. The stings can cause many symptoms including burning, swelling, nausea, extreme pain and numbness. Very unpleasant stuff.

The even fuzzier caterpillar.
Image by Amizrachi, CC BY-SA 4.0, via Wikimedia Commons

Unfortunately for us, the adult stage of the puss moth doesn’t last very long, which means the venomous caterpillars are around a lot longer than the friendly moths. The adults only live for about a week, and usually lay their eggs the night they emerge from their cocoon. The larvae go through a number of moults, getting hairier with each stage. When they are ready to build their cocoons, the caterpillars spin a thin framework of silk and then detach their hairy coats to complete their cosy sleeping bag. It’s a handy technique, but kind of gross in a way.

While puss moth caterpillars are not the only venomous caterpillars in the world, they are the most venomous species in the US, so be carefully around really fuzzy, cute things. They could be dangerous.

Cover image by Judy Gallagher, CC BY 2.0, via Wikimedia Commons