What should I watch for to recognize processionary caterpillars while hiking in the Serra de Tramuntana?

Along the pine-lined slopes of the Serra de Tramuntana, processionary caterpillars may be encountered between late winter and early spring. These small creatures are notable for their unusual habit of moving in single-file processions, making them easier to spot if you look closely on tree trunks or crawling across the ground. Their bodies are covered in fine, irritating hairs that can provoke skin rashes or allergic reactions, so it’s best to give them a wide berth.

Their coloring blends well with the pines—usually a grayish or pale blue hue with subtle dark markings along the back. You might also notice distinctive silken webs nestled among the branches of Aleppo pines, which serve as protective shelters for these caterpillars. These nests appear as wispy white clusters and are a good visual clue that processionaries may be nearby.

For anyone exploring well-trodden routes such as the Ma-10 towards Soller or paths around Valldemossa, awareness of processionary caterpillars is important. Although fascinating, avoid touching them and keep pets and children away to prevent skin irritation. If removal is necessary, local advice suggests using tools and protective gloves to prevent direct contact. Observing these insects from a safe distance allows you to respect the balance of the island’s unique forest ecosystem without risk to your health.