A tiny grey object clinging to a wall can easily be mistaken for dust, lint, or dried debris. However, it may actually be the protective case of a plaster bagworm, also known as a household case-bearing moth larva.

These insects create portable cocoon-like shelters using silk mixed with materials found around the home, including hair, fabric fibres, cobwebs, dust, and dead insects. The larva lives inside the case and slowly carries it across walls, ceilings, cupboards, and other quiet areas.

Plaster bagworms are especially common in warm, humid spaces such as bathrooms, garages, laundry rooms, and poorly ventilated cupboards. They do not bite people or spread disease, but larger numbers may become a nuisance and can occasionally damage natural materials such as wool, silk, or stored fabrics.

Removing visible cases is usually straightforward. Vacuum walls, corners, skirting boards, cupboards, and spaces where lint or cobwebs collect. Improving ventilation and lowering indoor humidity can also make your home less attractive to them.

Finding one does not necessarily mean your house is dirty. These insects can appear wherever moisture and suitable debris are available. Still, repeated sightings suggest it is time for a thorough clean and closer inspection.