Meet the Brown-tail Moth (Euproctis chrysorrhoea)

The female lays one cluster of 200 to 400 eggs, typically on the underside of a leaf. The egg cluster is covered with hairs from her anal tuft.[8] The larva is very hairy, brown with white markings, and two prominent red spots toward the tail end. The hairs provide protection from predators; the larva incorporates some into the cocoon within which it pupates.[9] The species overwinters communally as larvae within a tough, silken tent constructed around branch-tip leaves and anchored to twigs. In areas where the species is abundant, these tents are a familiar sight, and can be seen on a huge range of plants, especially in late fall and winter when unaffected leaves have fallen.[3][5]