Quick facts
- Size
- About 1/16 to 1/8 inch
- Looks like
- Small, dark brown to black, in long trails
- Peak season
- Late April through July
- Where in Michigan
- Statewide, especially homes on slabs and near sidewalks
- Main risk
- Nuisance and food contamination, not structural
- Risk level
- Low
Signs you have ants
- Lines of small ants along counters, baseboards or window sills
- Small piles of sand pushed up from cracks in sidewalks, patios and slabs
- Ants gathered around pet food, sugar or the dishwasher
- A rotten coconut smell when you crush an ant (odorous house ants)
- Winged ants indoors on a warm spring or summer day
Common house ants in Michigan
Pavement ants nest under sidewalks, driveways, patios and concrete slabs. In spring you may see them in large groups on a sidewalk, which are fights between neighboring colonies. They come inside through cracks in a slab, expansion joints and gaps along the foundation, and they eat almost anything, from crumbs and grease to pet food.
Odorous house ants are small, dark ants that smell like rotten coconut when crushed. They like sweets and often move indoors after heavy rain or a sudden change in weather. They nest in mulch, under stones and landscape timbers, and in wall voids. Colonies can have many queens and split easily, which makes them stubborn.
Other ants you may see include little black ants, tiny thief ants near kitchens, and field ants that build mounds in lawns. Large black ants indoors, especially in early spring, are a different issue and can point to damp or damaged wood. See our carpenter ant guide if that sounds like what you have.
Why ants show up indoors in a Michigan spring
Once the frost leaves the ground, colonies wake up hungry and start sending out scouts. A wet spring, which Michigan gets often, floods nests and pushes ants into homes. Hot, dry spells in midsummer can bring them inside again, this time looking for water around sinks, dishwashers and bathroom fixtures.
Homes on slab foundations, homes with mulch beds piled against the siding, and kitchens with a dishwasher or sink on an outside wall tend to see the most activity. Ant problems usually fade by September and October as colonies slow down, then start over again the next April if the colony under your slab is still there.
Baits beat sprays for house ants
Spraying the trail kills the ants you see, but the colony just sends more. Some sprays also cause odorous house ant colonies to split into new ones, which spreads the problem. Slow-acting baits work better. Workers carry the bait back to the nest and share it, which is the only practical way to reach the queens.
Put bait right on or next to the trail, leave the ants alone while they feed, and keep the area free of competing food. You may see more ants for a day or two, then numbers should drop within a week or two. Follow the label and keep bait away from children and pets. If ants ignore one bait, try a different type, sweet or protein.
What you can do yourself
- 1Place ant bait stations or gel along trails and leave the ants undisturbed while they feed.
- 2Wipe counters with soapy water to remove scent trails after the colony is gone.
- 3Store sugar, honey, syrup and pet food in sealed containers.
- 4Pull mulch back a few inches from the foundation and trim plants off the siding.
- 5Seal cracks in slabs and gaps where utility lines enter.
- 6Fix leaks and dry out areas under sinks.
When to call a licensed pro
- Ants keep coming back after several rounds of baiting.
- You find large black ants or winged ants inside walls.
- Ants are nesting in wall voids or under a slab you cannot reach.
What ants treatment costs in Michigan
$125 to $350per treatment
Typical Michigan ranges, not quotes. Price depends on the type of ant, home size and whether you choose a single visit or a seasonal plan.
Typical ranges, not quotes. See the full Michigan pest control cost guide.
Ants: common questions
Why do I have ants every spring?
Many colonies live permanently under your slab, sidewalk or yard. Each spring they become active and forage again. Sealing cracks, pulling mulch back from the foundation and baiting early in the season, as soon as the first scouts appear, can keep numbers down.
Do vinegar or cinnamon get rid of ants?
They can wipe out scent trails and deter ants for a short time, but they do not reach the colony. For lasting results, use a bait that workers carry back to the nest, and keep food and water sources cleaned up while the bait works.
Are winged ants a sign of termites?
Not always. Many ants produce winged swarmers. Ants have a pinched waist and bent antennae, while termite swarmers have a straight waist and straight antennae. If you find winged insects inside in spring, read our termite guide and save a few for identification.
Are house ants harmful?
Pavement and odorous house ants do not damage structures and rarely bite. They contaminate food and are a nuisance. Large ants chewing wood are a different matter and should be identified, since they may point to moisture damage.