Pest identification guide
Pavement Ants: Identification & Indoor Entry
Small dark ants entering at floor level may be travelling from a nest beneath a slab, rather than living in the cupboard where they find food.
Property-specific help across Southwestern Ontario and the 401 corridor.
Recognise the pest
How to identify pavement ants
Pavement ants are brown-to-black ants around 3–4 mm long, with fine parallel lines on the head and thorax. Those small features are not always visible in a phone picture, so colour or the fact that an ant is on a patio should not be treated as confirmation.
Their nesting locations help explain the pattern indoors. Soil beneath slabs, gaps between walls and spaces under patio slabs can support nests. In slab-on-grade houses, expansion joints or the wall-floor junction may provide access from a subterranean nest.
Where to look and what to record
Use accessible observations to guide an inspection. Do not disturb a nest, handle an animal or enter a hazardous area to obtain evidence.
Floor and wall junctions
Record repeated entry at the same edge or joint, particularly in a slab-on-grade part of the building.
Patios and slabs
Note nearby ant activity beneath or between slabs without lifting heavy materials or disturbing concealed services.
Accessible food
They prefer greasy and oily foods, but also eat insects and sweet things. Record the food associated with the sightings.
Behaviour and why it matters
An ant seen feeding in a kitchen can have travelled there from a nest below or beside the building. That makes the entry route and surrounding construction relevant to inspection. Treating the kitchen as the only affected area can overlook the connection with soil or slab gaps.
There is no fixed timeline for getting rid of pavement ants. A good plan starts with identification, noting where they get in and monitoring, rather than promising a set number of days.
An inspection-led approach
Practical next steps
These steps follow an integrated pest management (IPM) approach: identify the pest, find the source, then treat. They are not instructions for selecting or applying a pesticide.
Map the route
Write down the floor joint, doorway or wall edge where the ants repeatedly appear. Include whether activity is also visible outside.
Reduce accessible food
Clean food and grease spills and keep storage areas orderly. Simple sanitation like this goes a long way.
Discuss maintenance with treatment
Ask the technician to assess entry gaps and the suspected nest area. Agree which building repairs are appropriate and what signs to monitor after the visit.
Pavement Ants: common questions
Why are pavement ants coming through a floor joint?
They nest beneath slabs and get in through expansion joints and where walls meet floors. Repeated sightings there are useful inspection evidence, although identification still matters.
Do pavement ants only eat sugary food?
No. They prefer grease and oils, and also eat insects and sweet foods. Cleaning only one kind of spill may leave other food available.
Are all small black ants pavement ants?
No. Their small size and dark colour overlap with other ants. The fine markings, nesting location and other identifying features should be considered together.
Will sealing one visible crack solve the entire problem?
One opening does not establish the full extent of a nest or all access routes. Identification, inspection, prevention and follow-up work together, so repairs should be part of the plan.
Compare related pest guides
General information and safety notice
This guide is not a site inspection, confirmed pest identification, pesticide-use instruction, or medical, veterinary or legal advice. Do not choose, mix or apply a pesticide based on this page. Follow the current product label and your technician's written preparation and aftercare instructions. Avoid disturbing nests, handling wildlife or contaminated material. Treatment scope, timing, follow-up and any warranty are subject to the service terms confirmed for your property.
Help for your property
Talk through the problem before you book.
Tell us what you have seen, where it appears and how long it has been happening. We will discuss the options and confirm the service scope.