When are silverfish most active?

Silverfish are typically active midnight–4am.

What is silverfish activity commonly mistaken for?

Silverfish are most often confused with firebrats, earwigs. Use two pieces of sensory evidence — droppings plus sound, or smell plus damage — before you commit to a treatment plan.

Is it legal to treat silverfish yourself in the UK?

Silverfish are not a protected species in the UK and can be controlled without a licence, but you must use approved methods. The Prevention of Damage by Pests Act 1949 also obliges occupiers to keep premises free of rats and mice — councils can serve notice if they don't.

Is my landlord or me responsible for silverfish removal in a UK rental?

If you rent, the landlord is normally responsible for silverfish when the cause is structural (gaps in brickwork, broken air-bricks, drain defects, shared loft) or when the infestation pre-dates your tenancy. Tenants are usually liable when the cause is hygiene, food storage or items they brought in. Report it in writing first — that creates the paper trail councils and deposit schemes look for.

Will my UK council deal with silverfish for free?

Most UK councils still offer silverfish treatment, but coverage varies sharply. Around a third now charge £70–£180 per visit, some only treat rats and mice for free, and waiting lists in cities can run 1–3 weeks. A private BPCA-member controller is typically same-day or next-day and gives you a written guarantee, which councils rarely do.

Signs of
silverfish
in the house.

Spotting a silver, fast-moving teardrop-shaped insect in the bath at night is the everyday opener — and a sign of damp as much as a sign of silverfish.

Confidence rule — Silverfish almost always indicate humidity above 75% — fix the damp first and numbers usually crash.

◉ Four senses — what to check

See it. Hear it.
Smell it. Find it.

01 — See

Silver teardrop shape, bristle tail

10–12mm, silver-grey, with three bristles at the tail and a fish-like wriggling movement. Most often seen in the bath, sink or behind books.

02 — Hear

Silent

Silverfish make no audible noise.

03 — Smell

Damp, not silverfish

Any smell associated with silverfish is the damp environment they thrive in.

04 — Damage

Etched paper, glue and starch

Tiny ragged feeding marks on wallpaper, book bindings, photographs and starched fabrics. Yellow staining on stored linen.

◉ Where they shelter

Behind tiles, baths and bookshelves.

Anywhere humid and dark — behind the bath panel, under tiles, in the void behind a kitchen sink, and in the cool damp space behind a bookcase against an external wall.

◉ When activity peaks

Silverfish are
active midnight–4am.

Time of activity is one of the fastest ways to confirm a species — daytime loft noise rules out rats, midnight kitchen scuttling rules out squirrels.

◉ Urgency trigger

When to call today, not next week.

Visible black mould nearby — silverfish are a leading indicator that a damp survey is needed.

Emergency silverfish response →

◉ Still not sure — rule these out

Often mistaken for silverfish.

◉ UK FAQ — silverfish

Questions UK households
ask about silverfish.

What are the first signs of silverfish in a UK home?: Spotting a silver, fast-moving teardrop-shaped insect in the bath at night is the everyday opener — and a sign of damp as much as a sign of silverfish.
When are silverfish most active?: Silverfish are typically active midnight–4am.
When should I call a pest controller about silverfish?: Visible black mould nearby — silverfish are a leading indicator that a damp survey is needed.
What is silverfish activity commonly mistaken for?: Silverfish are most often confused with firebrats, earwigs. Use two pieces of sensory evidence — droppings plus sound, or smell plus damage — before you commit to a treatment plan.
Is it legal to treat silverfish yourself in the UK?: Silverfish are not a protected species in the UK and can be controlled without a licence, but you must use approved methods. The Prevention of Damage by Pests Act 1949 also obliges occupiers to keep premises free of rats and mice — councils can serve notice if they don't.
Is my landlord or me responsible for silverfish removal in a UK rental?: If you rent, the landlord is normally responsible for silverfish when the cause is structural (gaps in brickwork, broken air-bricks, drain defects, shared loft) or when the infestation pre-dates your tenancy. Tenants are usually liable when the cause is hygiene, food storage or items they brought in. Report it in writing first — that creates the paper trail councils and deposit schemes look for.
Will my UK council deal with silverfish for free?: Most UK councils still offer silverfish treatment, but coverage varies sharply. Around a third now charge £70–£180 per visit, some only treat rats and mice for free, and waiting lists in cities can run 1–3 weeks. A private BPCA-member controller is typically same-day or next-day and gives you a written guarantee, which councils rarely do.