These little guys look innocent enough, maybe even cute in a caterpillar kind of way. You might even be tempted to pick one up and let it crawl around a bit. Be forewarned that if you do it will likely mean the beginning of weeks of misery. This is the caterpillar of the brown tail moth, an invasive species commonly seen in Maine in the spring and summer. In addition to devouring the leaves of local deciduous trees, the thing that makes these caterpillars so troublesome is that their hairs are filled with a toxin that can cause severe itching and pain similar to that of a poison ivy rash. The hairs can also become airborne and drop from trees onto unsuspecting travelers. Breathing the hairs can cause respiratory distress and require medical attention. Over the counter remedies such as hydrocortisone, diphenhydramine, and lidocaine offer some relief, but there is no cure for the caterpillar toxin and prevention is the best way to avoid the dreaded itch. Stay clear of the caterpillars and their nests which take the form of a tangled, tent-like web woven between the branches of trees and shrubs. Thankfully, caterpillar encounters and severe reactions to the caterpillar toxin are relatively rare and shouldn’t dissuade anyone from visiting Acadia this season. Due caution will help to ensure that your visit remains pleasant and itch-free.