Quick facts
- Common species
- Black garden ant (Lasius niger); pharaoh ant (Monomorium pharaonis) indoors
- Size
- Garden ant about 4 to 5 mm; pharaoh ant about 2 mm, pale yellow to light brown
- Nest
- Under paving, patios and lawns; pharaoh ants nest in warm wall voids and cavities
- Season
- Flying ant days in summer, often in July or August in warm weather
- Behaviour
- Follow scent trails; sugar and protein attract them
How to identify ants
The black garden ant is the usual culprit in summer. A colony may live under a patio or beside the house and send workers in through gaps to feed on sugar, crumbs and pet food. Flying ants are winged males and new queens leaving the nest to mate. They appear in large numbers on warm, humid days and are harmless but alarming.
Pharaoh ants are different. They are very small, pale and nest indoors in warm wall cavities, behind kitchen units and in heating ducts. They are common in blocks of flats, hospitals and restaurants, and a colony may contain many queens and spread by 'budding' when it is disturbed.
Signs of ants in your home
- Trails of ants along walls, worktops and skirting boards
- Ants gathering around sugary spills, pet food or bin areas
- Piles of fine soil or sand around patio edges and pavements
- Large numbers of winged ants emerging in warm weather
- Tiny pale ants in kitchens or bathrooms all year round, a sign of pharaoh ants
Risks and damage
Garden ants do not usually harm health but can contaminate food. Pharaoh ants can carry bacteria between places and are a hygiene risk in kitchens and healthcare settings. Large colonies under paving can destabilise slabs over time.
Why ants come into properties
Ants follow food and moisture. Warm, dry weather, crumbs, open food and tiny gaps around doors, windows and pipes let them in.
How to prevent ants
- Wipe up sugary spills and crumbs promptly and store sweet foods in sealed containers
- Do not leave pet food out and rinse recyclables before binning
- Seal cracks and gaps around windows, doors and pipes
- Keep bins clean and tightly closed
- Do not just spray visible ants, as this scatters trails and can make pharaoh ant problems spread
Professional ant control by Southwark Pests
For garden ants, baits or targeted treatments around nest sites and entry points are usually effective. For pharaoh ants, professional gel baiting is the normal approach, because ordinary sprays scatter the colony and make it larger. Treatment of pharaoh ants should be coordinated across all affected flats.
A good technician will identify the species first. The wrong treatment, particularly for pharaoh ants, makes the problem worse.
When to call a professional
Call a professional if ants keep coming back, if you suspect pharaoh ants (very small pale ants indoors all year), or if you run a food business or live in a block where neighbours also have ants.
Ant control across Southwark and London
Black garden ants find their way into ground-floor kitchens all over South London in summer. In heated blocks, hospitals and offices, tiny Pharaoh ants can be a year-round problem that needs specialist baiting. We cover South London, Central London (the City, the West End and Westminster), East London out to Stratford and Newham, and nearby parts of Kent, from our base at South Dock Marina in SE16. A standard visit is £90, and you can book online or call 020 8050 2022.
- Southwark
- Bermondsey
- Peckham
- Camberwell
- Rotherhithe
- Lambeth
- Brixton
- Lewisham
- Greenwich
- Bromley
- Bexley
- Kent
- Central London
- City of London
- Westminster
- East London
- Tower Hamlets
- Hackney
- Newham
- All areas
Ant control: questions and answers
Why do I get flying ants?
Flying ants are mature colonies releasing winged queens and males to mate. They appear in warm, humid weather and last a day or two.
Are flying ants dangerous?
No. They are a nuisance, although some can sting or give a mild bite. Vacuum them up if they come indoors.
What are pharaoh ants?
A tiny tropical ant that survives indoors in heated buildings and spreads between flats. It needs professional baiting.
Do ants cause damage to my property?
Mostly no, though large colonies under paving may disturb slabs and some species nest in damp timber.
How do I stop ants coming into the kitchen?
Clear food sources, clean surfaces, seal gaps and block trails. If it recurs, locate the nest or call a professional.
Does vinegar work on ants?
It can disturb a scent trail temporarily but does not remove the colony.
Related pages
This page is general information, last reviewed on 19 October 2026. It is not a substitute for an on-site inspection.