Pinworms have smooth bodies bilateral symmetry and complete digestive tracts what type of animal are they?

Pinworms are a type of parasitic roundworm belonging to the phylum Nematoda. They exhibit bilateral symmetry, have smooth, elongated bodies, and possess a complete digestive tract, which distinguishes them from flatworms. Pinworms primarily inhabit the intestines of their hosts, particularly humans, where they can cause infections leading to discomfort and itching.