It's a Tussock Moth Caterpillar, and it's venomous. Not the fatal type of venomous, but as my son just found out, it's a pretty unpleasant experience.

On Tuesday afternoon, my son Spencer and I were sitting on the patio at home, about to go in and have lunch.

As he stood up, his hand went to the back right-side of his neck and he swept something away that had been crawling on him. When I looked down to see what he'd knocked to the ground, I saw an unusual looking caterpillar.

Here's the culprit (right before being terminated by an angry mom):

Amy Jacobsen, Townsquare Media
Amy Jacobsen, Townsquare Media

It was a White-Marked Tussock Moth Caterpillar. I knew that because I'd recently read a piece online about venomous caterpillars. I read that piece because we'd seen another one crawling on some backyard flowers about a week before.

The caterpillar has a built-in defense mechanism located in those tufts of hair. The venom contained in those hairs is released when the hairs become embedded in your skin upon contact. That venom can cause anything from a minor irritation to a very nasty (but not life-threatening) allergic reaction.

I assumed that because there were two touches involved (where the caterpillar was crawling on his neck, and on his hand when he swept it away) my son would have two areas that would need quick attention. I went straight to Google to see what we needed to do to mitigate the consequences of it being on his skin.

Strangely enough, the caterpillar only nailed him on one of those spots. His neck:

Amy Jacobsen, Townsquare Media

We also found it odd that initially, he showed no signs whatsoever of having been exposed to the venom. However, when it did announce itself, it brought some serious itching, burning, and overall discomfort. What you see above didn't show up for several hours, and by the time we photographed his neck it was looking a lot better than it did at first. We treated it with ice and calamine lotion, and he seems to be healing up quickly.

Just wanted to share the experience with you in case you should find one of these caterpillars hanging around your place. Keep your kids and pets clear of these guys. Sure, they're pretty, but they may leave a lasting impression on anyone who decides to touch one.