Silverfish (Lepisma saccharina) are slender, fast running, wingless insects that are approximately a centimetre and a half to two centimetres in length. They are metallic silvery-blue in colour with antennae at the front of their bodies and three long bristle-like tails protruding from their rear end. Their fish-like darting movements and their colour gave rise to their name. These insects are very ancient creatures having been around for over 300 million years and are found throughout the entire world but are especially associated with human habitats.

How do silverfish breed?

The male silverfish lays his spermatophore (basically a capsule containing his spermatozoa) which is then taken up by the female for fertilisation, who of course will then produce fertilised eggs. The female silverfish will lay her eggs in small cracks and crevices in places that are damp and warm. The eggs will hatch usually between two weeks to two months later depending on the conditions prevalent at the time. When the young silverfish emerge, they will look just like smaller versions of the adults and will reach maturity in about six months.

Where do silverfish like to live?

They favour moist, humid places so can be found in and around shower rooms, bathrooms, toilets, kitchens, damp floors, cupboards (particularly under the sink), sinks, windows, old pipes and skirting boards. Sometimes they can become trapped in the bath or the sink as they slide down whilst foraging for food and are unable to climb back up the slippery surfaces. You can suspect the presence of silverfish in your home if you find yellowy stains on paper or material, evidence of scales or excrement, or if books and wallpaper look notched or damaged at the ends. They don't like the light and are nocturnal by nature so will usually been seen scuttling around the floors, pipes and skirting boards at night, which is also when they like to feed.

What do silverfish eat?

Silverfish like to feed on just about anything and are particularly attracted to starch and polysaccharides. They will eat away at adhesive bindings or anything containing glue substances, photographs, cotton and other material and fibres, wallpaper, wallpaper paste, books and papers, detergent residues, shampoo, shaving foam and other toiletries containing cellulose, dried and powdered foods, cereals, leather, and have even been known to feed on dead insects at times.

How do silverfish get in the house?

They can quite easily be transferred into the house inside cardboard boxes, old books or papers, or on any starched fabrics as well as other materials.

How do I get rid of silverfish?

Silverfish are not harmful to humans but they are considered a nuisance pest, particularly if they are present in large numbers. You can treat existing infestations of silverfish yourself quite easily with a residual insecticide making sure that you apply it to window frames, skirting boards, cupboards and shelves under the sinks, floors around the toilet and bath, pipes, cracks and crevices and anywhere else that you suspect they may be lurking. You could also try airing rooms regularly to prevent a build up of moisture and treating any damp areas as silverfish cannot survive in dry conditions. Another option is to remove or at least restrict their food supply by clearing up old books and newspapers that are lying around, making sure that any detergents or residues from shampoos and other toiletries are thoroughly rinsed away and that all containers are properly sealed. However, removing their food supply as the only means of prevention is not effective as silverfish are able to survive for many months without any food at all.