Larvae look like caterpillars. They are slow-moving and difficult to see, as often they burrow inside the fibers of clothing for protection. Larvae are the culprits for clothing damage—a single caterpillar can spend up to six months feeding on an article of clothing before advancing to the pupa stage.
Moth caterpillars build cocoons on their journey to adulthood. These can be constructed out of spun silk or foraged materials, depending on the species. Webbing moths build cocoons from silk, while casemaking moths build cocoons from fibers. Typically, casemaking moth cocoons are easier to identify due to their durability.