If you’ve ever spotted a trail of ants marching through your kitchen or invading your outdoor patio, you’re not alone. Ants are one of the most common household pests in St. Louis, and once they find a food source, they can be incredibly persistent.
But not all ants are the same. Some are just a nuisance, while others—like carpenter ants—can cause structural damage. The key to eliminating them is identification. In this blog, we’ll cover the most common ants found in St. Louis, how to spot them, and when it’s time to call in the professionals at STL Pest Control.
1. Why Are Ants a Problem in St. Louis?
The warm, humid summers and mild winters in Missouri make our area a perfect breeding ground for ants. They invade homes looking for food, moisture, and shelter, especially during the spring and summer months.
Ants can:
✅ Contaminate food by crawling over surfaces and into pantries.
✅ Damage wood (carpenter ants tunnel through structures).
✅ Be difficult to eliminate, as some species split their colonies when disturbed.
Since different types of ants require different treatment methods, knowing which species you’re dealing with is crucial.
2. The Most Common Ants in St. Louis
Odorous House Ants
🔍 Size: Small (1/8 inch), dark brown to black.
🛠️ Signs: Give off a strong, rotten coconut-like smell when crushed.
🏠 Where They Nest: Indoors in walls, under sinks, and near moisture; outdoors under logs and rocks.
🍽️ What They Eat: Sugary foods, honey, and household crumbs.
Pavement Ants
🔍 Size: Small (1/8 inch), brown to black with fine ridges on their heads.
🛠️ Signs: Often seen trailing along sidewalks, patios, and basements.
🏠 Where They Nest: Cracks in driveways, pavement, and under foundations.
🍽️ What They Eat: Sweets, proteins, and greasy foods.
Carpenter Ants (The Most Destructive)
🔍 Size: Large (1/4 to 1/2 inch), black or black with reddish hues.
🛠️ Signs: Sawdust-like debris (frass) near wooden areas, hollow-sounding wood.
🏠 Where They Nest: Moist or decayed wood (attics, decks, crawl spaces).
❗ Why They’re a Problem: Can cause serious structural damage by tunneling through wood.
Argentine Ants
🔍 Size: Small (1/8 inch), light to dark brown.
🛠️ Signs: Large ant trails moving in and out of homes.
🏠 Where They Nest: Moist areas (bathrooms, under appliances, behind walls).
🍽️ What They Eat: Sugary foods and proteins.
❗ Why They’re a Problem: Multiple queens make them hard to control.
Pharaoh Ants
🔍 Size: Tiny (1/16 inch), yellow to light brown.
🛠️ Signs: Large colonies found in hospitals, kitchens, and businesses.
🏠 Where They Nest: Inside walls, electrical outlets, and behind appliances.
🍽️ What They Eat: Grease, proteins, and sugary foods.
❗ Why They’re a Problem: Colonies split into multiple nests when disturbed.
Acrobat Ants
🔍 Size: Medium (1/8 to 1/4 inch), light brown to black.
🛠️ Signs: Raise their abdomen over their head when threatened.
🏠 Where They Nest: Decaying wood, tree stumps, sometimes inside homes.
❗ Why They’re a Problem: Can strip insulation from electrical wiring.
3. How to Identify Which Ants Are in Your Home
🧐 Look at size and color – Are they small, medium, or large? Light or dark?
📍 Check where they’re nesting – Inside, outside, in wood, or in pavement?
🐜 Observe their movement – Are they in trails, scattered, or swarming?
🧪 Use bait stations – Different ants prefer different foods, which can help identify them.
4. Prevention & DIY Control Tips
To reduce the chance of an ant infestation, follow these tips:
✔️ Keep food sealed – Store sweets, grains, and pet food in airtight containers.
✔️ Clean up crumbs and spills – Even tiny food particles attract ants.
✔️ Fix leaks and reduce moisture – Ants need water sources to thrive.
✔️ Seal cracks and entry points – Use caulk around doors, windows, and foundation gaps.
✔️ Trim vegetation near your home – Keep branches and shrubs from touching your house.
✔️ Use ant baits – Baits are more effective than sprays because they target the colony.
If ants keep coming back despite these efforts, it’s time for professional treatment.
5. When to Call a Professional Exterminator
While DIY methods can work for minor infestations, some ant problems require expert help.
📌 Call STL Pest Control if:
✅ Ants keep returning no matter what you try.
✅ You suspect carpenter ants, which can cause structural damage.
✅ Ants are in walls or electrical outlets, making them hard to reach.
✅ You have a large colony, such as Argentine or Pharaoh ants.
✅ You need safe, long-lasting treatment that won’t harm pets or kids.
At STL Pest Control, we use advanced ant control treatments that target the entire colony, not just the visible ants. Our team has over 30 years of experience helping St. Louis homeowners keep their homes pest-free. We offer customized solutions to fit your needs—whether it’s baiting, exclusion, or professional-grade treatments.
📞 Need Help? Call STL Pest Control Today!
If you’re dealing with an ant infestation, don’t wait until it gets worse. Call STL Pest Control to schedule an inspection today!
Ants are a common nuisance in St. Louis, but knowing which type you’re dealing with can help you find the best solution. While DIY prevention can help in some cases, professional treatment is often necessary for persistent or destructive species like carpenter ants.
For fast, effective, and expert pest control, contact STL Pest Control today!