Entity scope
This profile centers on the common silverfish, Lepisma saccharinum, while acknowledging related silverfish-like household insects. Firebrats remain distinct; not every bristletail-like insect is this species.
Quick identity
- Scientific name
- Lepisma saccharinum
- Body
- Flattened, tapered, scale-covered, wingless insect
- Appendages
- Long antennae and three tail-like filaments
- Typical color
- Silvery or gray when scales are intact
- Lookalike limit
- Related silverfish-like insects and firebrats require comparison
- Visual status
- NO_VISUAL — no unverified species image introduced
Key characteristics
- The body is flattened and carrot-shaped, tapering toward three posterior filaments.
- Silvery scales can be rubbed off and color alone is not decisive.
- Long antennae and fast movement support bristletail identity.
- Firebrats are typically mottled and favor warmer settings, but close comparison is still needed.
Life stages
01
Juvenile
Smaller wingless form; scales develop after early molts.
02
Adult
Silvery scale-covered wingless stage with long antennae and three tail filaments.
Where it is found
- Dark, humid rooms, bathrooms, basements, storage, books, boxes, wall voids, and sheltered crevices.
- Related bristletails can favor different heat and moisture conditions.
Behavior and activity
- Silverfish are fast-moving and mostly active in darkness.
- They feed on starchy or protein-containing materials but small numbers do not prove meaningful damage.
- Humidity supports context but does not diagnose a building defect.
Diet and resources
- Starches, paper sizing, book bindings, wallpaper paste, cereals, and compatible organic material.
- Material damage needs direct evidence rather than proximity alone.
Associated signs
A specimen plus compatible resource is stronger than holes or stains alone.
Common lookalikes
Mottled warm-area bristletail species with different thermal context.
Related groups may share the tapered wingless form.
Much smaller soft-bodied psocids associated with humidity and fungal resources.
Why it matters
A nuisance and material-feeding context, not a moisture diagnosis
Common silverfish may damage starchy materials in sufficient numbers, but one insect does not prove an infestation, unsafe mold, or structural water damage.
- Confirm the species-centered traits while preserving related bristletail alternatives.
- Keep verified material damage separate from assumptions based on room humidity.
Management direction
- Photograph the scales, body taper, antennae, and tail filaments.
- Compare the temperature and habitat context with Firebrats.
- Use the existing Guide for full inspection and management after identity and activity are supported.
Related Guides
Have a pest photo to check?
Start a new photo identification. This Profile gives comparison context; it does not transfer certainty or diagnose your image.
Identify a photoReviewed guidance and sources
Last reviewed August 2026. Sources support the claims listed with them; their limits remain part of the review.
- Penn State Extension — Bristletails (Silverfish and Firebrats)
Supports: Common silverfish and firebrat species names, body form, scales, appendages, habitat, resources, and lifecycle context.
Does not support: Identity of every silverfish-like insect as Lepisma saccharinum or proof of damage from one sighting.
Scope note: North American household context; related species occur elsewhere.
- GBIF — Lepisma saccharinum
Supports: Current taxonomic species identity and accepted spelling for Lepisma saccharinum.
Does not support: Household behavior, damage, or management claims.
Scope note: Taxonomic occurrence aggregator; behavior requires separate sources.