Ann Arbor calls itself Tree Town, and its ants agree. Mature maples, oaks and ash trees line most residential streets, offering dead limbs, hollow trunks and root zones in which ants build nests. When spring warms the city, carpenter ants start moving in the trees, pavement ants begin working at sidewalk cracks, and the smaller odorous house ants find their way into kitchens. Much of the older housing stock only makes it easier for them.
PestMinistry is a referral service. We connect callers with independent, licensed ant control providers serving Ann Arbor. We do not treat homes ourselves.
Which ant is that?
- Carpenter ants are large, black or black-and-red. They excavate damp wood and often have a parent nest outside, such as in a tree or stump, with satellite nests inside the house.
- Odorous house ants are small and brown, with a rotten-coconut smell when crushed. They form big, multi-queen colonies and trail to sweets.
- Pavement ants nest in soil under slabs, paving and foundations, and carry sand to the surface.
- Citronella ants are yellow subterranean ants that sometimes swarm indoors, often indicating soil moisture around the foundation.
Why Tree Town homes attract carpenter ants
Old maples and oaks suffer storm damage and heart rot, which creates ideal nesting wood. Branches that touch roofs make a bridge. Victorian and early-twentieth-century houses in Burns Park, the Old West Side and Water Hill have complex rooflines, wooden porches and trim that stay wet in the shade. Chimney flashing, window sills, bathroom walls and kitchen sink cabinets with slow leaks create perfect interior nests. Telltale signs include pencil-shaving frass, quiet rustling in walls and large winged ants in the spring.
Treatment steps
- Observe ant trails at dusk, track them to the entry point and look for moisture and decay.
- Place baits for sweet-feeding species and let workers carry them back to the nest.
- For carpenter ants, treat nests directly, using dusts or foams in wall voids and perimeter products outdoors.
- Correct leaks and replace damaged wood.
- Recheck to confirm that activity has stopped.
Prevention
- Trim limbs and shrubs so they do not touch the house.
- Have hazardous or hollow trees evaluated, and remove stumps near the home.
- Clean gutters and repair flashing before spring.
- Keep wood mulch and firewood away from the siding.
- Wipe crumbs, drips and pet dishes at night.
- Seal cracks around windows, doors and pipes.
Understanding the seasons
Winged carpenter ants appear in spring and early summer, which can alarm residents who confuse them with termites. Foraging peaks in summer, especially after rain. In fall, ants search for warmth. Midwinter activity indoors in Ann Arbor means a nest in the building, perhaps near a chimney, furnace or leaky pipe, and it should be investigated promptly.
Reach a provider
Call (844) 725-1661 to be connected with a licensed provider serving Ann Arbor.
Frequently asked questions
Are carpenter ants dangerous to my house?
They can weaken damp wood over time, so early treatment and moisture repair are important.
Why do I see ants after a thunderstorm?
Rain floods nests and drives foragers toward dry shelter, including your home.
Is spraying the trail a good idea?
It can make odorous house ants spread into new nests. Baiting is usually more effective.
How can I tell termites from flying ants?
Look at the waist, antennae and wings. Ants have narrow waists, bent antennae and unequal wings.