You may have seen them on the news, or even out when you are walking around town or the woods. I am talking about caterpillars, oak processionary caterpillars in particular.

Southern Europe is the home of the oak processionary moth, but in recent decades they have been found all the way up to England, Germany and Denmark. In Southern Europe the moth has native predators, but in the north, they can grow undisturbed and during the spring its caterpillar lives to eat everything green in sight. While they are quite annoying for gardeners and farmers, they caterpillar is also dangerous for humans and pets. The caterpillar’s body is covered in small, spiky hairs that contain thaumetopoein, a toxin which can cause asthma attacks and vomiting when breathing them in and is also known to result in dizziness, fever, and eye and throat irritations. Results can also be prominent rashes that itch up to several days and even pink eye if the hairs get in your eye. The main problem is that the hairs do not only cause a reaction when your skin comes in contact with the caterpillar, but they can be carried by the air too.

Not only we are at risk, our pets can be just as affected by them as we can. Eating or just sniffing the caterpillars could result in illness in cats and dogs, with symptoms including hyper-salivation, tongue swelling, gagging, breathing problems and mouth inflammation, to the point of the tongue partially dying off.

The tricky part is that you can’t always see them, they caterpillars blend in well with the trees bundling up in large colonies and spinning a net around themselves. You may notice them moving from tree to tree or along the tree trunk in a large procession, hence the name.

So, what can you do if you notice a nest like that? If the nest is in an area that is trafficked a lot, like a playground or park, notify the community… they will remove them or block off the area. If you spot them in your private yard, notify your landlord so he can hire someone for removal, or contact an exterminator. Do not try to remove these pests on your own.