Quick answer
A pavement ant is a small, dark brown to black ant, Tetramorium immigrans, that nests in soil under sidewalks, driveways and building slabs and comes indoors through cracks to feed on sweets, grease and crumbs.
Pavement ants are a nuisance, not a structural pest. The small piles of sand they push up along pavement cracks and slab joints are the easiest sign, and slow-acting baits are the main control.
Quick facts
The key facts about Pavement Ant, with sources:
Key takeaways
- Pavement ants live under concrete and come inside through slab and foundation cracks.
- Look for tiny sand piles along sidewalk cracks or where the floor meets the wall.
- They eat almost anything that hits the floor, from sugar to grease to dead insects.
- They do not damage buildings, but they can girdle young garden plants.
- Slow baits that workers carry home work better than sprays on the trail.
The small dark ant under your sidewalk
Pavement ants get their name from where they live. Most colonies sit in soil under sidewalks, building slabs and large rocks 1. When they dig, they push soil and sand up through cracks, leaving small piles along the edges of pavement.
Penn State gives workers a length of 2.5 to 4 mm, dark brown to black 1. Up close, the head and thorax have fine parallel grooves, the waist has two segments and two short spines point up and back from the rear of the thorax 1.
The species came from Europe. Penn State says it was likely carried to the United States in the holds of merchant ships in the 1700s to 1800s, and it now ranges from New England to the Midwest and south through the Mid-Atlantic to Tennessee 1.
It is one of the most common house-infesting ants in Pennsylvania 1.
You may also see an older scientific name, since many publications, including UC IPM’s ant guide, still call it Tetramorium caespitum 4; newer sheets use T. immigrans 13.
A nuisance pest, not a wood pest
University of Maine Extension says pavement ants do not damage homes or buildings 2. They are not carpenter ants or termites, even when they swarm indoors.
How pavement ants end up in a kitchen
- Colony under concrete: The nest sits in soil beneath a slab, walk or patio 1.
- Scouts search: Workers forage up to about 30 feet from the colony 23.
- Entry through cracks: They come in through cracks in foundation walls and interior slabs 12.
- Food found: Sweets, grease, dead insects, seeds, pet food and crumbs all qualify 12.
- Trail forms: Workers lay a scent trail that others follow. UC IPM says wiping trails with soapy water removes that scent 4.
- Swarms indoors: In heated buildings, winged ants can emerge any time of year, even from late fall into February 1.
- Nest under slabSoil beneath concrete
- ForagingUp to about 30 feet out
- Crack in slab or foundationEntry point
- Food on floorSweets, grease, crumbs
- Scent trailRecruits more workers
Pavement ants and the ants they are mistaken for
| Ant | Size and color | Waist nodes | Thorax spines |
|---|---|---|---|
| Pavement ant | 2.5–4 mm, dark brown to black 1 | Two 1 | One small pair 12 |
| Thief ant and Pharaoh ant | Tiny, pale | Two 4 | None 2 |
| Acrobat ant, European red ant | Varies | Two | Longer spines than pavement ants 2 |
| Odorous house ant | About 1/8 inch, dark brown to black; strong smell when crushed 4 | One 4 | None |
| Argentine ant | About 1/8 inch, dull brown 4 | One 4 | None |
A hand lens helps with these checks. If the ant is larger and has one node, see our carpenter ant page; if it stings hard and builds sunny mounds in the South, see fire ant. The pest identifier covers more.
Example: finding the source of a winter ant trail
This illustration shows how published facts point to the nest. The scene is made up; the facts are sourced.
| What you notice | Published fact | What it tells you |
|---|---|---|
| Small dark ants in a basement in January | Swarming late fall into February is not unusual in heated buildings 1 | The colony is likely under the heated slab |
| Sand piles at a crack in the basement floor | Sand or soil near slab cracks signals nesting nearby 1 | That crack is a likely entry |
| Ants carrying crumbs from under a pet bowl | Nearly any food on the floor may be eaten 1 | Clean up the food source |
| Workers 30 feet from the crack | Foragers range up to about 30 feet 2 | Bait near the crack, not where you see stragglers |
The result: place bait close to the crack where the ants enter, clean the floor, and seal the crack once the ants stop coming. Penn State says control may take two weeks or longer 1.
Where you will see the term
On an ant control service ticket, the technician may write “pavement ants” with the areas treated, such as the slab edge, foundation cracks or patio. Good tickets name the product type, for example “gel bait” or “bait station,” and where it was placed.
On a recurring pest control plan, check whether pavement ants are covered as a general nuisance ant, and whether ant callbacks between visits are included.
On a garden or farm report, pavement ants may be named for girdling seedlings. University of Delaware documented this in vegetable transplants 3.
Signs of pavement ants
- Small piles of sand or soil along sidewalk and driveway cracks 1.
- Sand or soil at slab cracks or at the top of foundation walls indoors 1.
- Trails of small dark ants to food on floors 1.
- Winged ants indoors in winter in heated buildings 1.
- Young garden plants collapsing with ants at the base of the stem 32.
Keep baits away from kids and pets
Penn State says to place baits where ants are active but out of reach of children and pets 1. Do not use outdoor products indoors, and follow every label. For a suspected poisoning, call Poison Help at 1-800-222-1222.
Why baits beat sprays for pavement ants
Baits
What baits and sealing cannot do
You cannot remove every outdoor colony, and UC IPM says total elimination outdoors is unrealistic; the aim is to keep ants out of buildings and take away food and water 4.
Baits work slowly: Penn State says control may take two weeks or longer, and used bait needs replacing 1. UC IPM adds that fewer ants may show in 5 to 10 days, but full control can take weeks 4.
In gardens, options are limited. University of Delaware found that ant labels exist only for certain baits, insecticides labeled for vegetables do not list ants, and organic options such as diatomaceous earth, pepper sprays or boiling water did not clear damaging colonies 3.
What drives the cost of pavement ant control
We do not list prices, because cost varies with how many entry points there are, whether baits need several refills, and whether the work is a one-time visit or part of a plan.
Sealing cracks in slabs and foundations is the longest-lasting fix and may be handyman work rather than pest work. Our recurring plan tool compares one-time and ongoing service, and the pest control cost guide explains how quotes are built.
A step-by-step plan for pavement ants
- Confirm the ant: Check for the grooved head, two-node waist and small thorax spines 1.
- Find the entry: Look for sand at slab cracks and the top of foundation walls 1.
- Clean up: Store food sealed, clean spills and grease and fix leaks 4.
- Bait: Place a labeled ant bait where ants are active, out of reach of children and pets, and keep it stocked 1.
- Do not spray near the bait: UC IPM says not to use sprays while baiting 4.
- Seal: Once ants stop showing, caulk cracks and openings around the foundation 4.
If ants persist after a few weeks, a professional can find hidden entries. See our ant control service page.
Keeping pavement ants outside
- Caulk cracks in slabs and foundations and around pipes and wires 4.
- Keep food in sealed containers and pet food off the floor overnight 4.
- Wipe up spills and grease the same day 4.
- Keep mulch and plants back from the foundation; UC IPM’s quick tips say at least a foot 4.
- Fix leaks that keep soil under slabs damp 4.
A quick fix for a fresh trail
UC IPM says wiping or vacuuming a trail with soapy water removes the scent other ants follow. Petroleum jelly can plug an entry hole as a stopgap 4.
Our guide to caulking for pest prevention covers which sealants suit which gaps.
When to call a professional
Call if ants keep coming back after a few weeks of baiting and cleaning, if you see swarms indoors repeatedly, or if you cannot find where they enter.
Call too if you are not sure of the ant. Carpenter ants and termites need different treatment, and swarming pavement ants can look like either at first glance.
Rules that apply
Federal (EPA, FIFRA): Any ant bait or spray must be EPA-registered and used as its label says. University of Delaware stresses reading labels, since many products do not list ants or the site 3.
State water rules: In California, UC IPM notes the Department of Pesticide Regulation limits outdoor perimeter treatments with pyrethroids because of water pollution 4. Other states have their own rules.
Licensing: Pest control companies are licensed by the state. See pest control licensing and our pesticide safety guide.
Pavement ant vs carpenter ant vs termite swarmer
| Feature | Pavement ant | Carpenter ant | Termite swarmer |
|---|---|---|---|
| Size | 2.5–4 mm workers 1 | 1/4–1/2 inch workers | About 1/4 inch (eastern subterranean) |
| Waist | Two nodes 1 | One node 4 | Broad, no pinch 4 |
| Antennae | Elbowed 5 | Elbowed 5 | Straight 5 |
| Damages wood? | No 2 | Digs nests in wood | Colony eats wood |
If a swarm has straight antennae and equal wings, read our page on termite swarmers.
Common pavement ant myths
- Myth Ants swarming indoors in winter must be termites.
- Reality Pavement ants can swarm in heated buildings from late fall into February 1. Check the waist and antennae 5.
- Myth Spraying the trail solves it.
- Reality Sprays kill foragers, not the colony; control is temporary 4.
- Myth Pavement ants damage the foundation.
- Reality They do not damage buildings 2; they use cracks that already exist.
- Myth Natural powders and boiling water will clear them.
- Reality University of Delaware found these did not eliminate damaging colonies in its trials 3.
Where pavement ants are common
Penn State lists the pavement ant’s U.S. range as New England through the Midwest, south through the Mid-Atlantic to Tennessee 1; UC IPM also covers it in its California ant guide 4.
In colder states, indoor activity in winter is tied to heated slabs and basements, not outdoor weather 1.
On the Delmarva Peninsula, University of Delaware recorded pavement ants tunneling out watermelon transplants in 2020 and 2021 and girdling cabbage and broccoli transplants in 2024 and 2025 3.
When it matters to you, and what to do next
Where the ants are decides the response. Ants outdoors along pavement can usually be left alone, while ants trailing indoors call for cleaning, bait near the entry and sealing once they stop. For winged ants indoors, check the waist and antennae to rule out termites, then treat them the same way.
If you hire help, ask whether the plan uses baits, where they go and when the cracks will be sealed. Our guide to choosing a pest control company lists more questions.
Bait near the entry
- Reaches the queen under the slab
- Slower: two weeks or more
- Do not spray near it
Spray on the trail
- Kills the ants you see
- Colony keeps sending more
- Can trap ants indoors
Quick decision guide
Ants only outdoors can usually be left alone. For an indoor trail, clean, bait, then seal. For winged ants indoors, rule out termites first.
Questions about Pavement Ant
What do pavement ants look like?
Pavement ants are small, dark brown to black ants about 2.5 to 4 mm long, according to Penn State. Under a magnifier, you can see fine parallel grooves on the head and thorax, a two-segment waist and two short spines pointing up and back from the thorax. Winged swarmers are about twice the worker size.
Why do pavement ants make piles of sand?
Pavement ants nest in soil under sidewalks, driveways and slabs, and they push the soil they dig up through cracks. Penn State says sand or soil near slab cracks or at the top of foundation walls can signal a nearby nest. The piles are often the first sign people notice.
Are pavement ants harmful?
Pavement ants are mostly a nuisance, and University of Maine Extension says they do not damage homes or buildings. They can contaminate food on floors and, when food is short, girdle young garden plants. Penn State notes they carry a stinger, but our sources do not describe them as a human sting problem.
Why are there ants in my house in winter?
Ants indoors in winter are often pavement ants nesting under a heated slab or basement floor. Penn State says winged pavement ants can emerge any time of year in heated buildings, and swarming from late fall into February is not unusual even in cold climates. Check the ant to rule out termites.
What is the best way to get rid of pavement ants?
The best way is a slow-acting ant bait placed where the ants are active, combined with cleaning up food and sealing cracks. Penn State says workers carry bait back to the nest and can wipe out the colony, though it may take two weeks or longer. Avoid spraying near baits.
What do pavement ants eat?
Pavement ants eat almost anything: Penn State lists sweets such as sugar, nectar, fruit and syrups, plus grease, dead insects and small seeds, and says nearly any food that falls to the floor may be eaten. University of Maine adds meats, grains, garbage, pollen, pet food and nuts.
How far do pavement ants travel from the nest?
Pavement ant workers forage up to about 30 feet from their colony, according to University of Maine Extension and University of Delaware. That means a trail in your kitchen may come from a nest under the patio or driveway, so bait near where the ants enter, not just where they eat.
Do pavement ants damage plants?
Sometimes, yes. University of Delaware recorded pavement ants tunneling out watermelon transplants in 2020 and 2021 and girdling cabbage and broccoli transplants in 2024 and 2025 on the Delmarva Peninsula. University of Maine notes they girdle brassicas, tomatoes and carrots when food is scarce. This is uncommon in home gardens but does happen.
Sources
- Penn State Extension, Pavement Ant, retrieved .
- University of Maine Cooperative Extension, Pavement Ants, retrieved .
- University of Delaware Cooperative Extension, Ants in My Plants: Pavement Ant Feeding on Vegetable Transplants, retrieved .
- UC Statewide IPM Program, Pest Notes: Ants (Publication 7411), retrieved .
- U.S. EPA, Termites: How to Identify and Control Them (ant vs termite features), retrieved .
Expert review
Written by the HyrePest Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Identification, range, nesting, food and bait guidance follow Penn State Extension, University of Maine, University of Delaware and UC IPM Pest Notes 7411, attributed to each. Ant-versus-termite features are from the EPA.
Suggest a correction. We fix errors and say what changed.