What do processionary caterpillars look like on Mallorca and how should I react if I find one?

Walking through pine forests near the Serra de Tramuntana or shaded trails around Alcudia, you might spot a string of small caterpillars moving in a neat, head-to-tail line. These processionary caterpillars have a distinctive furry coat of fine hairs, usually greyish with subtle lighter stripes, making them quite conspicuous on the bark or under pine branches. Their tendency to travel in single file—almost like a living chain—is an unmistakable trait that draws attention.

Despite their intriguing appearance, it’s wise to keep your distance. The hairs of these moth larvae can cause unpleasant skin irritations or allergic reactions not only in people but also in dogs and other pets commonly walked in the countryside here. If you find one or stumble upon their silky nests woven high in pine trees, avoid touching them. Local services on the island sometimes monitor these caterpillars, especially when infestations threaten forest health. Reporting sightings to environmental authorities helps manage their impact, safeguarding both visitors and the island’s treasured woodland.

Exploring Mallorca’s natural landscapes is a joy, but respect for the wildlife—such as these processionary caterpillars—and a cautious approach ensures your time in places like Soller or Formentor stays safe and enjoyable. Observing them from a safe distance offers a glimpse into the island's rich biodiversity without risk.