bunch of caterpillars on the ground

animals biology brown catepillars caterpillar centipede centopiedi close closeup colony crawling crawly creepy detail dirt entomology environment follow grey ground hairy insects irritant larva larvae lepidoptera line macro natural nature nest outdoors parasite people pine pityocampa procession processional processionaries processionary pupa species thaumetopoea thaumetopoeidae together transformation wild wilderness wildlife worms