How to get rid of Silverfish Guide
Silverfish are on the rise in the UK. Read this guide to find out where they come from, what attracts them and most importantly, how to get rid of silverfish.
Once a hallmark of dodgy university flats, silverfish are becoming more common for UK homeowners and renters. These prehistoric bugs thrive in humidities of between 55-70%. They feast on starch and cellulose, which can be found in damaged books, loose papers and wallpaper paste, amongst other common household items.
What are Silverfish and what do they look like?
The Common Silverfish, or Lepisma saccharinum, are insects around 20mm long. Befitting their namesake, they are light grey or silver in colour. Silverfish are relatively unchanged from prehistoric times. Like many other insects, they have long antennae extending from their heads.
Silverfish boast a few rare features from their prehistoric origins. Three antennae-like protrusions extend from their back half. Two outer Caudal filaments detect dangers like predators and harmful chemicals.
In the middle is the median caudal filament. This unique appendage is only found in primitive insects like the silverfish. This strangely specialised antennae-like feature detects the air current.
The Silverfish is also unique for what it lacks. Unlike most insects, Silverfish do not have any wings. It is still an agile creature, able to scuttle across the floor with ease. Its unique movements resemble a wiggling fish, hence the name Silverfish. When spotted, Silverfish will try to escape back to their harbourage. Follow them quickly to find where they’re nesting in your home.
Researchers have recently discovered another type of Silverfish species in the UK. The grey Silverfish, or Ctenolepisma longicaudata, was first found in 2014 and is spreading across the UK. It is also known as the Long-Tailed Silverfish. The Grey Silverfish is longer and hairier than Lepisma saccharinum. Its antennae and tails are also much longer.
Like the Silverfish, paper is their favourite food source. However, they consume it at a much faster rate. Grey Silverfish live in lower humidity atmospheres than Silverfish. Grey Silverfish are most comfortable at around 60% relative humidity. To protect book collections or paper records, Grey Silverfish infestations must be quickly brought under control.
Although firebrats are separate species from silverfish, they are very similar in appearance and habits. Firebrats, also known as Thermobia domestica, look like Silverfish. They are also sometimes known as Banded Silverfish. Their main distinguishing feature is their brown-red scales.
Firebrats love high temperature and high humidity environments. They prefer even higher temperatures than silverfish but can live in areas of lower humidity too. Check around kitchen appliances and boiler rooms. A Firebrat infestation can be tackled like a silverfish infestation.
What attracts silverfish?
Silverfish are attracted to moist areas of high humidity. You are most likely to find them in wall void spaces, basements or ceilings and dark, undisturbed corners. Look behind refrigerators and around boiler rooms. Silverfish hate light and stay confined to dark areas.
Silverfish will harbour near available sources of water. Ensure your home is free of leaks and pools of standing water. Inspect drainage system and all pipework. Make sure pet bowls are put away after feeding time.
In the garden, ensure there are no piles of dead leaves or wood adjoining the property. Like Woodlice, Silverfish are comfortable under rocks, inside rotting wood or leaf piles.
Why do I have silverfish?
If Silverfish have moved into your house or flat, it means two things.
- The atmosphere contains high humidity levels
- there are readily available starch, cellulose and moisture sources
Ensure the air can freely circulate within your home. High humidity causes condensation, which encourages mould growth.
What do silverfish eat?
Silverfish eat starch and cellulose. They are well known for their book demolishing powers. As well as paper, they consume a wide range of things around the home. They are capable of eating carpets, clothes, photos, sugar, some types of glue and adhesive like wallpaper paste. They can eat book adhesive as well as the pages themselves.
They will happily eat food crumbs. Regularly clean kitchen surfaces and floors. Pack all loose foods in airtight containers.
Be warned! Silverfish can live for up to a year without food as long as they have access to a water source, so repair leaks and mop up standing pools of water.
Do Silverfish bite?
Silverfish do not bite humans, although they eat insect carcasses. Silverfish often engage in cannibalism. They eat defenceless moulting Silverfish as well as discarded exoskeletons. While Silverfish do not attack humans, they will happily eat dust and dead skin cells.
How do silverfish get in your house?
Silverfish are capable of squeezing into small gaps. They gain entry into the home through damaged doors, windows and walls. Spalled masonry and other damp-related defects attract Silverfish infestations. These types of damage offer ways into the home and a moisture source.
Silverfish often sneak into homes undetected. Their nocturnal nature and tendency to avoid danger in the home mean they can multiply unnoticed. Silverfish can climb walls, although they trade some of their horizontal speed to do so.
Where do silverfish come from?
In the natural world, Silverfish live in similar places to woodlouse. They find refuge in rotting wood, under rocks and among fallen leaves.
More efficient insulation and rising temperatures have caused more silverfish infestations in UK homes. They seek shelter in the home for protection from natural predators like spiders and centipedes.
How long do silverfish live?
Silverfish have long lifespans of up to three years. Female silverfish produce eggs throughout the year to lay around 100 eggs throughout their lifespan.
Silverfish eggs are hard to find because they hide their eggs in tiny cracks around the home. They are less than 1 mm long.
Silverfish eggs take around a month to hatch, although this may vary depending on the environment. Juvenile Silverfish are called Nymphs. Unlike other insects, Silverfish emerge from eggs as smaller versions of adult Silverfish. Apart from the size, you can tell a Nymph from an adult silverfish by their white exoskeletons.
The easiest and most obvious sign of a Silverfish infestation is the presence of the little creatures around the home. Silverfish are nocturnal – keep an eye out when the curtains are closed. Silverfish hide in dark, dank areas near food sources so look carefully behind bookshelves and corners, cracks and crevices. They are commonly found in the bathroom too.
Each silverfish moults its outer skeleton around 30 times a year. At first glance, Silverfish moults look a little like dead Silverfish. They are incredibly thin and much less colourful than the Silverfish themselves, being translucent. If you find moulted exoskeletons, you have a live silverfish infestation.
As they moult, silverfish secrete a yellow residue that stains porous surfaces. You might find it on books, papers, or wallpaper.
How do I get rid of Silverfish?
Secure all food and moisture sources
- Be aware of the foods Silverfish like to eat.
- Remove any loose stacks of paper, books, magazines, cardboard boxes or paper-based items.
- Vacuum regularly to ensure your home is free from dust.
Remove dead leaves and wood from the garden and outside areas
Secure access points
- Ensure windows and doors are free of defects, cracks and holes.
- There should be no gaps or breakages in rubber door seals
Lower the humidity
- Cooking, washing and cleaning all generate humid air. Keep your home ventilated by using ventilation systems, keeping windows open and ensuring air can freely circulate. Learn more about reducing condensation in the home here
Constant monitoring is a pillar of effective pest control. Following successful treatment, you should regularly carry out these steps to avoid new infestations.
- It’s time to search your home for active silverfish harbourages. By now you should know where to look: dark moist areas and small gaps. Try observing live Silverfish if you can find them. The places they scurry to will clue you in to where the rest are hiding.