Do pavement ants damage driveways or patios?

Pavement ants (Tetramorium immigrans) are one of the most common ants around New Hampshire hardscape, and their name describes their habit precisely: they nest in the soil and sand beneath slabs, pavers, and sidewalks, and along expansion joints and cracks. As they excavate their nest chambers, they carry sand and soil up to the surface and deposit it in small, volcano-shaped mounds — usually right at a joint or crack edge.

That excavation is the entire mechanism. There is no chewing of masonry, no dissolving of concrete, no acid secretion that eats into a slab. The ants are moving material that was already loose in a space that already existed — the joint or crack was there first, and the ants simply found it.

Multiple university extension sources are direct on this point: pavement ants are not known to cause structural damage, because they neither nest in nor eat wood or masonry — their entire activity is relocating soil. Penn State, NC State, and Virginia Cooperative Extension all describe pavement ants as a nuisance and indoor-foraging pest, not a structural one.

The "undermining your foundation" version of this claim seems to borrow language from genuine foundation-settlement problems and attach it to an ant that happens to nest near concrete. But causation runs the other way: pre-existing cracks, joints, and settling from freeze-thaw cycles create the voids pavement ants move into — the ants are a consequence of those gaps, not the cause of them.

In the worst realistic case — a large, long-established colony under an already poorly-bedded paver patio — the ongoing excavation can, over many years, contribute to minor settling or unevenness in individual pavers. That's a real, if slow and modest, effect on loosely-set pavers specifically. It is not evidence of damage to sound poured concrete or asphalt, and it never approaches cracked beams, tilted floors, or the other foundation-failure language sometimes attached to this claim.

The honest ceiling here is cosmetic: recurring sand mounds, some joint sand that needs periodic refilling, and ants that may find their way indoors along the same route. None of that requires structural repair.

If the mounds bother you, sweeping or hosing them away and caulking the joints reduces the visible nuisance, though the ants may simply re-excavate elsewhere along the same crack network. If pavement ants are also showing up inside your home — a common pattern, since the same cracks and joints that let them nest also let them forage indoors along your foundation — that's the point where professional perimeter treatment and baiting genuinely helps, because it addresses the colony rather than just the surface symptom.

What you should not do is treat this as a slab-repair problem. There's nothing wrong with your concrete that pavement ants caused, and no caulk, bait, or treatment changes the structural integrity of a driveway or patio that was already sound.