Who let the dogs out? caterpillar version.
Wiki: The Pine Processionary (Thaumetopoea pityocampa) is a moth of the family Thaumetopoeidae. It is sometimes placed in the genus Traumatocampa. It is an abundant species of pine woods in central and southern Europe, and an important economic pest. The species is notable for the behaviour of its caterpillar larvae, which overwinter in tent-like nests high in pine trees, and which process through the woods in nose-to-tail columns ..
source: Caterpillar caravan