Silverfish are small, moisture-loving insects commonly found in UK bathrooms, kitchens, and damp areas, where they feed on starchy materials and can damage books, wallpaper, and clothing.
Typical Cost
£60–£120
DIY Possible?
For mild cases
Season
Year-round
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The silverfish (Lepisma saccharina) is a primitive, wingless insect that has coexisted with humans for thousands of years. Measuring 10–15mm in length with a distinctive silvery, fish-like appearance and rapid, darting movement, silverfish are nocturnal and prefer dark, damp environments. While they are not a health hazard, they feed on starchy substances including book bindings, wallpaper paste, cardboard, flour, and even the sizing on cotton fabrics, making them a nuisance pest that can cause damage over time.
Using dehumidifiers, improving ventilation, fixing leaks, and using extractor fans in bathrooms and kitchens to lower humidity levels below 50%. Silverfish require high humidity (75%+) to thrive, and drying out the environment makes conditions inhospitable for them.
Applying a residual insecticidal powder (containing permethrin or deltamethrin) behind skirting boards, in cracks, around pipes, and in other harbourage areas. The powder remains active for several weeks, killing silverfish that cross treated surfaces.
Placing adhesive traps in areas where silverfish have been sighted — behind toilets, under baths, near bookshelves, and in kitchen cupboards. Useful for monitoring numbers and identifying the main harbourage areas, but unlikely to control a large population on their own.
Applying food-grade diatomaceous earth in cracks, crevices, and behind fixtures where silverfish hide. The powder damages their waxy outer layer, causing dehydration. Effective in dry conditions but loses its efficacy when damp, which can be a challenge in the humid environments silverfish prefer.
Storing books, papers, and cardboard in sealed plastic boxes rather than open shelves. Keeping dried food in airtight containers. Removing old newspapers, magazines, and cardboard boxes from damp areas. This reduces the food supply and makes the environment less attractive to silverfish.
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Professional silverfish treatment usually involves residual insecticidal spraying of affected areas, dusting of voids and crevices, and advice on environmental management to reduce humidity. The cost is generally at the lower end of the pest control scale. Addressing underlying damp problems (which may require a damp specialist) is usually more important and potentially more costly than the pest treatment itself.
Silverfish are active year-round in UK homes, as they inhabit heated indoor environments and are not strongly affected by outdoor temperatures. However, they may become more noticeable during autumn and winter when increased use of central heating and reduced ventilation raises indoor humidity levels through condensation. Bathroom and kitchen infestations are perennial. Silverfish have a long lifespan (2–8 years) and reproduce slowly, so infestations tend to develop gradually over months or years rather than appearing suddenly.
Silverfish do not bite, sting, or transmit diseases, so they are not a direct health risk. However, they can cause damage to books, wallpaper, photographs, and stored papers over time. Their scales and droppings may contribute to household dust allergies in sensitive individuals.
Silverfish thrive in warm, humid environments, making bathrooms an ideal habitat. They are attracted to the moisture from showers and baths, and they feed on organic matter including soap residue, toothpaste, and damp paper. Improving ventilation with an extractor fan and wiping down wet surfaces will make the bathroom less inviting.
A persistent silverfish population often indicates elevated humidity levels in the property. While a few silverfish are common in most UK homes, large numbers suggest a damp or ventilation problem that should be investigated. Addressing the underlying moisture issue is the most effective long-term solution.
The key to long-term silverfish control is reducing humidity below 50%, eliminating harbourage, and removing food sources. Insecticidal treatments can knock down existing populations, but without addressing the damp conditions that attract them, silverfish are likely to return. A combined approach of environmental management and chemical treatment is most effective.
Silverfish can climb most surfaces but struggle on very smooth ones such as glass, porcelain, and some plastics. They are surprisingly agile and can often be seen darting across bathroom walls and ceilings. Their ability to climb allows them to access bookshelves, cupboards, and even loft spaces.
Cockroaches are one of the most reviled pests in the UK, carrying serious disease risks and thriving in warm, humid environments such as kitchens, bathrooms, and commercial food premises.
Clothes moths and pantry moths cause costly damage to textiles, carpets, and stored food in UK homes, often going unnoticed until significant harm has been done.
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