Berlin is experiencing a significant surge in pine processionary caterpillars. These caterpillars possess hairs containing toxins that can cause skin irritation, rashes, and potentially severe allergic reactions in humans and animals. Authorities are advising residents to avoid contact with the caterpillars and their nests, particularly in forested areas. The caterpillars travel in a distinctive line, hence the name "processionary." Previous years have also seen outbreaks, but this year’s numbers appear particularly high. Residents are urged not to touch or disturb the caterpillars and to report sightings to local authorities. Symptoms from contact include skin rashes, eye irritation, and respiratory problems.