Some bugs play a helpful role in keeping your home pest-free, but others—like Phereoeca uterella, known in Javanese as kamitetep—can be damaging and difficult to detect. Commonly referred to as plaster bagworms or household casebearers, these tropical moths thrive in warm, humid environments and are often found in closets, garages, and basements. They’re most noticeable in their larval stage, when they carry around flat, gray cocoon-like cases made of fibers, dust, and debris. These portable cases act as protection and later become the pupal shell. The moths go through four life stages: egg, larva, pupa, and adult. Adults grow to about half an inch in length and are covered in grayish-brown scales.

Kamitetep feed on a wide range of materials, including lint, dust, hair, silk, wool, feathers, dead insects, and even paper—but they avoid cotton. This diet allows them to damage clothing, rugs, and important documents. They tend to hide in dark, humid spots near fabrics, cardboard boxes, baseboards, and light fixtures. To prevent or eliminate infestations, it’s essential to vacuum thoroughly, especially in corners and storage areas, remove visible cases, seal cracks, reduce indoor moisture, and declutter. Regular cleaning and airtight food storage are also effective deterrents. If DIY methods fail, insecticidal sprays or professional pest control may be necessary. Although kamitetep don’t bite or spread disease, they reproduce quickly and often feed on spiderwebs—so it’s helpful to alert exterminators if you notice spiders, too.