Adult : Small, silvery-beige colour, winged (though weak flyers); larvae : creamy white with brown/dark brown head. Larvae 10mm; Adult 6-8 mm.
Eggs (cluster of 50-100), oval, 0.5mm, 06-24 days; Life span of adult 2-3 weeks.
Found in hair, wool, fur, silk, feathers, nails, horns, hooves, any material of animal origin containing keratin, in homes, museums, etc. Larvae of T. bisselliella construct open ended web like feeding galleries while larvae of T. pellionella move about dragging a case made of silk and feeding material and hence are also called "bagworms".