Silverfish are small, primitive, wingless insects recognised by their flattened bodies, scales and quick, agile movements. They are members of the insect order Thysanura and are well adapted to living in quiet, undisturbed areas. In Australia, silverfish are commonly found in buildings where they can shelter in places such as bookcases, storage areas, cupboards, roof spaces and ceilings. They can cause damage by feeding on materials containing starches and other organic substances, including paper, books, fabrics, wallpaper and some stored items. Although silverfish do not pose a direct health threat to people, their presence can become a concern when they establish themselves indoors and begin damaging household or business belongings. Understanding where silverfish hide and what attracts them is an important part of preventing and controlling an infestation.

Silverfish are small, wingless insects with a flattened, slender body covered in fine scales. Their bodies are usually silver or grey in colour and taper towards the rear, giving them their distinctive fish-like appearance. They have long, slender antennae at the front of the body and three noticeable tail-like appendages extending from the abdomen. These three rear appendages are one of the most recognisable features of silverfish. Young silverfish have a similar body shape and appearance to adults, but are smaller. Unlike many other insects, they do not undergo a complete metamorphosis, so the young gradually develop into adults while retaining the characteristic silverfish shape.

Silverfish have a simple development cycle and do not undergo the complete metamorphosis seen in many other insects. Females lay eggs individually or in small groups, with eggs generally hatching within several weeks. The young silverfish resemble smaller versions of the adults when they emerge. They grow through a series of moults, gradually increasing in size as they develop. Depending on environmental conditions, silverfish may take several months to reach sexual maturity. Unlike many insects, silverfish continue to moult throughout their adult lives. They can live for several years, allowing established populations to persist for an extended period when suitable food, shelter and environmental conditions are available.

Silverfish are fast-moving, nocturnal insects that are generally active at night and tend to avoid light. During the day, they seek shelter in dark, quiet and relatively undisturbed areas. They can move throughout a building in search of food and suitable shelter, which means they may be found in a variety of rooms and storage areas rather than remaining in one location. Common hiding places include cupboards, bookcases, storage areas, roof spaces and other secluded parts of a property. Silverfish are unable to climb smooth vertical surfaces effectively. As a result, they can sometimes become trapped in smooth-sided baths, sinks and basins, making these locations a useful indication that silverfish may be active elsewhere in the property.

Silverfish can become a problem when they establish themselves inside homes, businesses or other buildings. They can shelter in a wide range of concealed areas, including roof cavities, wall voids, subfloor spaces, cupboards and other undisturbed parts of a property. Silverfish are attracted to materials containing starches, glues and other substances used in paper products and furnishings. They may damage books, book bindings, photographs, wallpaper and fabrics such as cotton and linen. Paper and photographs can be particularly vulnerable, with the smooth or treated outer surface sometimes showing signs of feeding damage. Because silverfish are active at night and can hide during the day, an infestation may go unnoticed until damage is discovered or silverfish are regularly seen indoors. Controlling an established population can help protect books, documents, furnishings and other valuable items from further damage.

Effective silverfish control begins with a thorough inspection of the property. Silverfish can be widely distributed and may remain hidden in roof cavities, wall voids, subfloor areas, cupboards and other concealed locations. Stored items may need to be moved or examined to identify signs of activity and locate potential harbourages. Depending on the extent and location of the infestation, professional treatment may involve a combination of control methods. Residual insecticide treatments can be applied to suitable surfaces where silverfish are likely to travel or shelter, providing ongoing control after application. In areas where liquid treatments are unsuitable, such as some roof or wall cavities, carefully applied dust treatments may provide an effective alternative. Space treatments may also be considered where silverfish are present throughout concealed or difficult-to-access areas. In some circumstances, appropriately positioned insecticidal baits can form part of an integrated treatment approach, although their effectiveness can be influenced by the availability of other food sources. Before treatment, reducing clutter and removing accessible food and paper sources can improve the effectiveness of professional control. Where silverfish are suspected within wall cavities or other inaccessible areas, treatment may require a more targeted approach. Professional silverfish management is most effective when inspection, treatment and preventative measures are combined to address both the insects and the conditions allowing them to persist.

Reducing the conditions that attract and support silverfish can help prevent activity and reduce the likelihood of an infestation becoming established. Silverfish are particularly attracted to quiet, enclosed areas and materials containing starch, glue and other organic substances. Check second-hand books, furniture and other stored items before bringing them into a home or business, as they may provide an opportunity for silverfish to be introduced. Books, documents, files and papers should ideally be stored in clean, dry and well-ventilated areas rather than being left undisturbed in tightly closed boxes or cupboards for long periods. Regularly opening and checking storage areas can help identify silverfish activity before significant damage occurs. Avoid excessive clutter and allow air to circulate around stored materials where practical. Valuable books, photographs and documents should be stored appropriately to reduce their exposure to potential pests. In kitchens and food storage areas, keep food in sealed containers and clean up crumbs, spills and food scraps promptly. Good housekeeping reduces available food sources and makes the environment less attractive to silverfish. Regular inspection is particularly important in areas that are rarely disturbed. Early detection, appropriate storage and good housekeeping can all contribute to an effective silverfish prevention and management program.