Finding an unfamiliar insect in your home can make it difficult to know whether you have seen an isolated visitor or evidence of a developing infestation.
Common crawling insects found in UK properties include silverfish, cockroaches, ants and several types of beetle. Correct identification matters because each pest is attracted to different conditions and may require a different approach.
This guide explains how to identify common crawling insects, where they are usually found and which warning signs require further investigation.
WHAT ARE CRAWLING INSECTS?
Crawling insects are insects that are commonly detected moving across floors, underneath cupboards, along wall edges and through cracks or gaps inside buildings.
Some crawling insects enter accidentally, while others live and reproduce indoors where they can access food, warmth, moisture or suitable materials.
Sticky insect traps can help establish which insects are active and where they are travelling. However, identification should also consider the insect’s appearance, the location in which it was found and any accompanying signs.
HOW TO IDENTIFY SILVERFISH
Silverfish are small, wingless insects with tapered bodies covered in silvery-grey scales. Their shape is often compared to a carrot or teardrop, with a broad head and narrow rear.
They have long antennae and three distinctive bristle-like appendages at the back of the body. Silverfish move quickly and may appear to wriggle as they run.
They favour dark, humid and relatively undisturbed areas, including:
- Bathrooms
- Utility rooms
- Under sinks
- Behind skirting boards
- Boiler cupboards
- Areas containing stored paper or cardboard
A silverfish sighting can indicate excess moisture, condensation or a hidden leak. Reducing humidity is therefore an important part of long-term control.
HOW TO IDENTIFY COCKROACHES
Cockroaches have flattened oval bodies, long antennae and prominent legs. Their colour and size vary by species, but cockroaches found indoors are commonly brown or dark brown.
They usually hide during the day and emerge at night. Seeing cockroaches in daylight may indicate that their hiding areas are crowded or that activity has become established.
Possible signs of cockroaches include:
- Live insects appearing at night
- Small dark droppings
- Shed skins
- Egg cases
- An unusual musty smell in a heavily affected area
Check behind refrigerators, cookers, dishwashers and other warm appliances. Cockroaches may also hide around plumbing, cupboards and narrow structural gaps.
HOW TO IDENTIFY ANTS IN THE HOME
Ants have clearly defined body sections, elbowed antennae and a narrow waist. They may enter properties in search of food and often form visible trails between a nest and a feeding source.
Ant activity is frequently found around:
- Kitchen floors and worktops
- Doors and windows
- Cracks in walls or flooring
- Food cupboards
- Pet feeding areas
Follow the direction of the trail to find the entry point. Cleaning away food residues may reduce activity, but recurring ants can indicate a nest nearby.
HOW TO IDENTIFY SMALL HOUSEHOLD BEETLES
Several beetle species may be found crawling indoors. Their significance depends on the species and where they are discovered.
Some beetles infest stored food, while carpet beetle larvae feed on materials of animal origin, including wool, fur, feathers and hair. Adult carpet beetles may be found near windows, but it is the larvae that cause textile damage.
Look for:
- Small oval or rounded beetles
- Hairy larvae or shed larval skins
- Damage to natural fabrics
- Beetles inside dry food products
- Repeated insects appearing near windows
If beetles are being found in food, inspect your pantry. If they are associated with damaged textiles, check wardrobes, carpets and stored fabrics.
WHY ARE CRAWLING INSECTS ENTERING YOUR HOME?
Crawling insects may be attracted by food, water, warmth, humidity or shelter. Common contributing conditions include:
- Food crumbs and spillages
- Unsealed dry food
- Pet food left accessible
- Leaking pipework
- Condensation and excess humidity
- Gaps around doors, pipes and skirting boards
- Cardboard and clutter stored undisturbed
Identifying and correcting these conditions can be just as important as capturing the insects themselves.
WHAT ARE THE SIGNS OF A CRAWLING INSECT INFESTATION?
One insect does not always confirm an infestation. Investigate further if you notice:
- Repeated sightings
- Several insects caught in the same area
- Droppings or egg cases
- Shed skins
- Damage to food, paper or textiles
- Activity in several rooms
- Insects appearing during daylight
Record where and when insects are seen. This information can help establish whether activity is isolated or continuing.
HOW STICKY INSECT TRAPS HELP WITH IDENTIFICATION
Sticky traps can provide a sample of the insects active within a room. Position several numbered traps in different locations and compare the captures.
A trap capturing insects underneath the sink may suggest a moisture-related problem, while captures behind an appliance may point towards warmth, food residue or a nearby hiding place.
The traps should be placed directly against edges because many crawling insects avoid travelling across open areas.
WHEN TO CONTACT A PEST-CONTROL PROFESSIONAL
Seek professional advice if you cannot identify the insect, captures continue to increase or you discover signs of an established cockroach infestation.
Professional support may also be appropriate when activity affects several rooms, returns after cleaning or occurs within a commercial or food-handling environment.
FREQUENTLY ASKED QUESTIONS
Why do I only see insects at night?
Many crawling insects avoid light and remain concealed during the day. Night-time activity can make traps particularly useful for detecting insects that would otherwise remain hidden.
Does finding one insect mean my home is infested?
Not necessarily. Continue inspecting the area and use traps to establish whether further activity is present.
Can sticky traps identify the source?
They can indicate where activity is concentrated, but you will still need to inspect nearby cracks, appliances, cupboards, pipework and moisture sources.
Are all crawling insects harmful?
No. Some are accidental visitors. Correct identification is necessary before deciding what action is appropriate.
THE KEY POINT
Do not rely on colour or size alone when identifying a crawling insect. Consider its body shape, the location where it was found and any associated signs. Use correctly positioned traps to monitor activity and direct your inspection towards the most active area.
