Pinworm

The human large intestine; during the night, females migrate to the perianal area to lay eggs.

Pre-digested material in the human intestine and intestinal bacteria.

Nematodes that live in the colon. Females travel to the anus at night to deposit thousands of sticky eggs on the surrounding skin.

Causes enterobiasis, characterized by intense itching in the perianal region; highly contagious among children and household members.