Silverfish and the wingless booklice found indoors can occur around paper, cardboard and stored goods in humid areas. The wider psocid group also includes winged species. They look different and cause different kinds of damage. Knowing which you have helps you choose the right response.
Silverfish
Silverfish are teardrop-shaped, silver-grey insects with three long tail filaments and two antennae. They move quickly in a fish-like wriggling motion. The University of Maryland Extension describes them as nocturnal insects that feed on starchy materials: paper, book bindings, wallpaper paste, cotton, linen and some synthetic fabrics.
In Singapore, silverfish are found in dark, humid areas: bookshelves, wardrobes, filing cabinets, storage boxes and bathrooms. They can damage books, documents, photographs and clothing by feeding on surface starches and creating irregular holes or surface scraping.
Booklice (psocids)
Booklice (psocids) are much smaller and soft-bodied. They do not look like silverfish and do not have the distinctive tail filaments. The University of Minnesota Extension describes booklice as feeding on fungi, grains, insect fragments and starchy materials including glue. They are commonly associated with humid conditions but are not solely mould feeders.
In Singapore, booklice are commonly found on damp walls, window frames, bookshelves and inside cupboards with poor ventilation. They can also appear in stored food packaging. Size and colour vary across species. For detailed management, see the booklice guide and the booklice treatment page.
Silverfish
Teardrop body, silver-grey, three tail filaments, fast wriggling movement. Generally larger than indoor booklice; sizes vary.
Cue: UMD silverfish
Booklice
Small, soft-bodied, no tail filaments. Size and colour vary across species.
Cue: UMN booklice
Illustrative only. Not to scale. Not a basis for species identification.
Key differences
- Size: silverfish are visibly larger than most booklice species, though exact sizes vary.
- Shape: silverfish have a distinctive tapered body with three tail filaments. Booklice are soft-bodied without tail filaments.
- Colour: silverfish tend to be silver-grey and shiny. Booklice are generally lighter, but colour varies across species.
- Movement: silverfish move quickly in a wriggling motion. Booklice tend to move more slowly.
- Feeding: silverfish feed on starchy materials and leave visible holes or scraping. Booklice feed on fungi, grains, starch and organic residues.
- Primary response: silverfish control may require targeted treatment. Booklice management focuses on reducing humidity and addressing food/moisture sources.
Sources: UMD silverfish and firebrats, UMN booklice. This guide provides general identification comparison; it is not a species diagnosis. Checked 15 October 2026.
Silverfish or Booklice FAQs
Do silverfish bite?
Silverfish do not bite people. They feed on starchy materials such as paper, book bindings and some fabrics.
Can booklice damage my books?
Booklice feed on fungi, starch and organic residues. They are associated with humid conditions. Reducing moisture and addressing food sources is the key response.
Do I need treatment for silverfish?
It depends on the numbers and the damage. A few silverfish in a bathroom may not need treatment. Persistent activity near valuable books, documents or clothing may warrant professional assessment.
Why do I keep finding both silverfish and booklice?
Both thrive in humid conditions. A home with consistently high humidity or damp storage areas can host both. Reducing humidity and improving ventilation helps with both.