How to Get Rid of Ants in the House

If you want to know how to get rid of ants in the house, start by understanding why they are coming indoors and how the workers are using the property. In many London homes, common black garden ants nest outside or close to the building boundary, then travel through concealed gaps to reach food. Effective control removes competing food, uses the active foraging route to deliver bait back towards the colony and avoids disrupting that process too early.

At Inoculand, we inspect and treat ant problems across London. Head Biologist Daniel Neves draws on these cases to explain how to identify the likely species, trace the active foraging route and use bait-led control without disrupting the colony too early.

Why ants come into houses

Understanding how to get rid of ants starts with identifying why they are entering the property. They usually come indoors for food and, less often, a reliable source of water. Kitchens provide the strongest attraction because crumbs, sugar, grease, fruit residue, pet food, bins and food packaging can all reward a scouting ant.

Only a very small amount of food is needed. Trails often lead towards a bread-cutting area, a dry-food cupboard, the floor beneath a table or debris beside an appliance. Once a scout finds a worthwhile source, it returns to the colony and recruits other workers, creating the organised line that the householder notices.

This trail is not random movement. It is a recruitment system that allows the colony to concentrate its workforce on a dependable resource. That behaviour is also what makes a carefully placed bait capable of reaching beyond the ants visible in the room.

Ant activity does not automatically indicate poor hygiene. A nearby colony may investigate a well-maintained kitchen, and only a few overlooked crumbs are needed to start recruitment. Cleaning removes competing food and improves bait uptake, but it does not affect the colony that continues to supply new workers.

Are ants in the house usually black garden ants?

In UK domestic properties, ants in the house are often common black garden ants. These are outdoor ants that become a nuisance when workers enter kitchens, living rooms or other ground-floor areas while foraging.

A localised trail of dark ants beside an external wall, kitchen unit or skirting board usually fits this pattern. The nest may be beneath paving, within soil or close to the building edge, while floors, skirting boards and kitchen-unit voids provide concealed access indoors.

The point where ants disappear should not automatically be treated as the nest. With ordinary garden ants, these spaces often act as protected transport routes from an outdoor colony.

When the same colony reaches its reproductive stage, winged ants may appear during warm weather. A sudden indoor emergence can look alarming, but these winged ants belong to the same colony rather than representing a separate pest. See our guide to flying ants in London for a fuller explanation.

Where garden ants usually enter London homes

Garden ants do not usually march straight through an open door or window. More often, an established indoor line disappears into a narrow gap at floor or skirting-board level, beneath a fitted kitchen unit or around a service penetration.

Outdoors, the corresponding route may run through failed paving grout, cracks between slabs or the joint where paving meets the external wall. The indoor emergence point is not necessarily the original entry from outside because the ants may have travelled through a subfloor space or another concealed void.

When deciding how to get rid of ants, observe the trail in both directions, but do not assume that you must locate the nest. Modern baiting relies on the workers finding bait in the foraging area and completing the hidden journey themselves.

Should you treat an outdoor ant nest?

Not every outdoor nest needs treatment. Ants form part of the garden ecosystem, so a nest in a lawn, flower bed or beneath a tree can usually be left alone when it is not affecting the property. The Royal Horticultural Society guidance on ants in gardens also advises tolerating garden ants where possible.

The position changes when a particular nest or route repeatedly sends ants into a kitchen, food area, living space or commercial premises. The aim is not to remove ants from the wider garden, but to control the colony affecting the building.

An outdoor nest may also need attention when activity beneath paving contributes to loose sand, rocking slabs or persistent high-volume trails at the building boundary. Even then, treatment should remain localised rather than covering lawns, flower beds or large areas of paving.

How to get rid of ants in the house step by step

The order of the work matters. Sprays, powders, bleach and sealants may reduce activity at one gap, but they can also kill or divert the workers needed for colony-level baiting. The best approach is to let the ants find the bait before removing competing food sources or sealing the gaps they are using.

1. Confirm that you have an active foraging trail

Watch where the ants gather and where the line disappears. A defined trail shows repeated movement between a food source and an established colony. One isolated scout does not always justify immediate pesticide use, but repeated sightings or a re-forming line show that recruitment is underway.

Focus on the immediate foraging area rather than trying to map the entire route. Check skirting boards, kitchen plinths, cupboard edges, pipe gaps, boiler cupboards, door thresholds and the corresponding external wall. The food source explains why the ants return, while the emergence point helps identify where bait is most likely to be found.

2. Place bait before removing the food they have found

Bait placement is an important part of how to get rid of ants without merely killing the visible workers. Always follow the product label and keep bait away from children, pets and food-contact surfaces. Place small amounts close to the active trail and feeding area, with additional placements nearby for scouting ants.

If the ants are feeding on crumbs, sugar or another residue, place the bait before removing that food. Once the bait is available, clean away the competing source while leaving the bait placements untouched.

When the workers return and the original food is gone, the bait remains in the same foraging area. This can improve uptake without requiring the nest to be located or exposed.

3. Allow the workers to carry the bait back

Ant bait works more slowly than a contact spray. The workers must remain active long enough to feed, return through the concealed route and distribute food within the colony. Through normal food sharing and colony care, the active ingredient can reach ants that never enter the room.

The delay is deliberate. A bait that killed workers immediately beside the placement would fail to exploit this transport system. Its value lies in allowing enough time for feeding and transfer before the affected workers decline.

This is why immediate knockdown is not always desirable. During baiting, the visible ants also act as the delivery system.

Do not spray or apply powder around the bait, along the trail leading to it or across nearby surfaces. Repellent residues may cause avoidance, while fast-acting products may kill the workers before they return to the colony.

4. Remove competing food without disturbing the treatment

Once bait is available, clean the surrounding worktop, floor, cupboard or feeding area. Pay particular attention to crumbs, grease, sugar, cereal, pet food and residue beneath appliances.

Cleaning removes the food that rewarded the scouts and reduces competition with the bait. Do not wipe away the bait or use strong cleaning chemicals immediately beside it.

5. Leave fitted units and hidden voids intact

There is normally no need to remove kitchen plinths, dismantle fitted units or open walls merely because ants disappear behind them. The hidden space may be a travel route rather than the nest itself.

Do not push sprays, powders, bleach or other pesticides blindly through the gap. This may kill travelling workers without reaching the colony and can cause the ants to emerge elsewhere.

Gel can be placed where the ants emerge, travel or gather food, allowing the workers to carry it through the hidden route themselves.

6. Seal obvious gaps after the activity has been controlled

Sealing can reduce future access, but it is not a substitute for treating an active colony. Closing the visible opening too early may simply redirect the ants through another gap.

Once the active trail has stopped, seal suitable cracks around skirting boards, pipe penetrations, thresholds and external paving joints. Exclusion is most useful as a final preventative step.

7. Monitor without repeatedly changing products

Knowing how to get rid of ants also means allowing sufficient time for the bait to work. Visible activity may continue for several days, and more ants may gather around a fresh placement once recruitment begins. This does not necessarily mean that the problem is worsening.

Leave the bait undisturbed and look for a sustained decline rather than expecting every ant to vanish immediately. The speed of control depends on the species, colony size, competing food and the bait being used. Judge progress by the overall reduction in recruitment and the disappearance of established lines, not by whether an occasional worker remains.

If a clear trail remains, reforms after an initial decline or appears in an untreated room, reassess the placement and renew the bait in line with the product label. Persistent or widely distributed activity may indicate another colony or a species that needs professional identification.

Ant killer, bait or spray: what works best?

The best answer to how to get rid of ants in the house is usually a treatment sequence rather than a single product. Cleaning, baiting, monitoring and later exclusion each have a different role.

For most household garden-ant problems, baiting should take priority over spraying. Where urgent local suppression is unavoidable, keep any spray clearly separate from the bait placements and routes used for baiting.

Spraying the baited area replaces slower colony-level control with faster suppression of visible workers. That may occasionally be necessary, but it should be a deliberate change of strategy rather than an automatic addition.

How to get rid of ants in the kitchen

Kitchens need the closest attention because food is usually the main reason garden ants enter. Identify the area they are exploiting, make suitable bait available and then remove competing food without disturbing the treatment.

• Clean beneath accessible appliances and along the edges of fitted units.
• Check bread-cutting areas, toaster trays and the floor beneath dining tables.
• Inspect dry-food cupboards for sugar, grains, flour, cereal and crumbs.
• Store food and pet food in sealed containers.
• Clean around bins, recycling containers, fruit bowls and pet bowls.
• Check gaps around sinks, washing machines, dishwashers and service pipes.
• Look for the corresponding route along skirting boards and the outside wall.

If ants emerge from behind a plinth or beneath a unit, keep the bait accessible and close to the visible foraging area rather than dismantling the kitchen.

Regular clean-as-you-go routines reduce the chance that another scout will find a dependable source and recruit a new line. They also make fresh activity easier to notice.

Are ants in bathrooms looking for moisture?

Sometimes, but moisture is not the only explanation. Common garden ants affect bathrooms less often than kitchens, especially upstairs. Where a ground-floor bathroom adjoins the kitchen, ants may use shared pipework, wall cavities or service ducts as a concealed route.

Repeated gathering around a leaking tap, shower edge or persistent condensation may indicate a genuine water attraction. A defined trail beside pipework, beneath a bath panel or along a wall shared with the kitchen is more likely to indicate travel through the building.

The species, floor level and relationship between adjoining rooms usually tell you more than moisture alone. Pharaoh ants differ because warm, humid service areas can form part of their permanent indoor habitat.

Why ants keep coming back

Ants return when a food source, active route or nearby colony remains available. They may also reappear from another gap after the first opening has been sealed. A single colony can use more than one route.

Seasonal recurrence does not always mean treatment failed. The practical answer to how to get rid of ants in the house may involve controlling the active colony, while a separate neighbouring nest could exploit the property later. Gardens can support several independent colonies.

Keep a record of where and when trails appear. Repeated activity in the same room and from the same building edge may indicate a persistent local route. Activity elsewhere later in the season could represent another route or colony.

Activity localised at ground level and limited to warmer months usually fits ordinary garden ants. Ants that remain active through winter, appear on several floors or spread through warm service areas need closer identification.

Could the ants be Pharaoh ants?

Not all small ants indoors are ordinary garden ants. Pharaoh ants can live and spread within heated buildings, service routes and interconnected flats. Repellent sprays can make control more difficult by disturbing colonies and encouraging them to divide.

Warning signs include:

• workers that are much smaller and paler than common black garden ants;
• activity in several rooms or on more than one floor;
• trails around warm pipework, boiler areas, electrical trunking or service ducts;
• persistent activity through cooler months; and
• similar reports from neighbouring flats or different parts of the same building.

Where these signs are present, avoid spraying and arrange identification before choosing a treatment. The strategy differs from the normal approach for a garden-ant trail entering a kitchen from outside. See our guide to Pharaoh ants in the UK for more detail.

When ants in the house need professional treatment

You may not need pest control for one isolated scout or a small trail that disappears after food removal. Professional treatment becomes more appropriate when the usual steps for how to get rid of ants in the house do not hold, a clear line keeps reforming, the route is hidden or the species is uncertain.

Further warning signs include large numbers emerging from one internal point, repeated indoor swarms, activity across several rooms or floors, or very small pale ants in a heated building. Ants affecting commercial food areas, rental properties and managed blocks may also need a coordinated response.

Commercial premises and managed blocks need a coordinated approach

The biological aim is similar in a domestic kitchen and a restaurant: reduce competing food and allow the workers to carry suitable bait back towards the colony. The operational demands, however, are different.

In commercial premises, the technician may need to consider food-safety procedures, customer-facing areas, operating hours, cleaning chemicals and staff responsibilities. Cleaning teams must know where bait has been placed so it is not removed during routine work. The bait must also be positioned in accordance with the product label and protected from food-contact surfaces.

Gel treatment is localised and can often be carried out without the broad disruption associated with spraying. However, access arrangements, temporary restrictions and working procedures depend on the product, location and site’s safety requirements.

In a block of flats, treatment may need to extend beyond the room or flat where ants were first reported. Shared pipework, risers, service ducts and adjoining rooms can connect separate areas of activity. Treating only one visible trail may overlook the wider pattern. Access and communication may therefore be as important as the pesticide itself, particularly where several occupiers or contractors share responsibility for connected areas.

Inoculand can assess the ants’ distribution, identify likely routes and consider whether the activity fits ordinary garden ants or a more complex indoor species. Treatment can then reflect both the ants’ biology and the practical conditions within the property.

What not to do when treating ants indoors

Knowing how to get rid of ants also means understanding which actions can undermine treatment. Avoid the following mistakes:

• Do not spray directly over bait, along the baited trail or on nearby surfaces.
• Do not place ant powder on kitchen worktops or inside food cupboards.
• Do not force sprays, powders or bleach into cracks or hidden kitchen voids.
• Do not dismantle fitted units merely to expose the route.
• Do not seal the only visible gap while the trail is still active.
• Do not clean away bait placements or contaminate them with strong chemicals.
• Do not assume that every small indoor ant is a common garden ant.

Killing visible workers can make the room look clear briefly without resolving the colony that replaces them. Effective baiting keeps the workers active long enough to transport treatment through the hidden route.

This requires patience. A treatment that does not produce an immediate line of dead ants may still be more effective than one that provides a dramatic surface kill.

When to call Inoculand for ant control in London

If how to get rid of ants in the house becomes a repeated question every spring or summer, stop relying on surface spraying alone. Wait for a genuine trail, identify the active foraging area and use a planned baiting approach. Once the colony has been controlled, remove attractants and seal suitable gaps.

Treating one colony cannot guarantee that another outdoor nest will never forage into the property later. It can, however, resolve the active problem without unnecessary spraying, dismantling or indiscriminate treatment of the wider garden.

A professional inspection is appropriate when trails keep returning, activity reaches sensitive food areas, ants appear across several rooms or the pattern does not fit ordinary garden ants. Its purpose is to understand the species, foraging behaviour, building routes and treatment sequence most likely to provide lasting control.