To get ants out of your room, you need to do three things: remove what’s attracting them, wipe out the scent trails they follow, and cut off their entry points. Killing the visible ants alone won’t solve the problem because they represent a tiny fraction of the colony. A combination of cleaning, baiting, and sealing works far better than any single step.
Find Where They’re Coming In
Before you do anything else, spend a few minutes watching the ants. They travel in lines, following invisible chemical trails left by scouts. Trace those lines back to where they enter the room. Common entry points include gaps along baseboards, cracks around window frames, spaces where pipes or wires pass through walls, and the edges of door thresholds. You may find a single entry point or several.
Knowing where ants enter tells you where to focus your cleaning, where to place bait, and what to seal once the infestation is under control.
Remove Food and Water Sources
Ants are in your room because they found something worth coming back for. In a bedroom, the usual culprits are crumbs from snacking, sticky residue from drinks, pet food bowls, or even a damp towel near a leaky window. In kitchens and bathrooms, it’s food residue, grease, and standing moisture around sinks and drains.
Pick up any food, wipe down surfaces, take out trash, and store anything edible in sealed containers. Even a single drop of soda on a nightstand can sustain a trail of ants for days. If moisture is the draw, fix the leak or dry the area thoroughly. Removing the reward makes every other step more effective because ants have less reason to keep returning and are more likely to take your bait.
Wipe Out the Scent Trails
Ants navigate by following pheromone trails, chemical signals left behind by other ants. Even after you kill every ant you can see, new ones will follow the same invisible path within hours. To break the cycle, you need to physically destroy those trails.
Mix equal parts white vinegar and water in a spray bottle and wipe down every surface where you’ve seen ant activity: the trail itself, the entry point, windowsills, baseboards, and the surrounding area. The vinegar disrupts the pheromone signals and its strong scent temporarily repels new scouts. Soapy water works similarly. Wipe rather than just spray, since the physical scrubbing helps remove the chemical residue. You may need to repeat this daily for the first few days as scouts try to re-establish routes.
Use Bait Instead of Spray
Your instinct will be to grab a can of bug spray, but that’s actually counterproductive. Spray kills the ants you can see while leaving the colony, including the queen, completely untouched. The colony simply sends more workers along a new path.
Ant baits work differently. They contain a slow-acting poison (typically boric acid or a compound that disrupts the nervous system) mixed into something ants want to eat. Workers carry the bait back to the nest, feed it to other ants and the queen, and the colony collapses from the inside out. This takes time. You’ll keep seeing ants for a week or more after placing bait, and that’s actually a good sign because it means they’re carrying poison home. Leave the bait in place for three to four days after you stop seeing any feeding activity.
Place bait stations directly along the trails you identified and near entry points. Don’t spray insecticide near the bait or clean the trails in the baited area, since you want ants to find and use the bait. If you’ve already wiped trails elsewhere, the bait becomes the most attractive option left.
Choosing the Right Bait
Ants are either looking for sugar or protein at any given time, and this shifts with the colony’s needs. If you set out a sweet gel bait and the ants ignore it, try a protein-based or greasy bait instead. Many people find success by offering both types. Liquid and gel baits tend to work better for the small household species (like odorous house ants and pharaoh ants) because workers can drink and share them easily.
Seal the Entry Points
Once ant activity drops off, seal the cracks and gaps where they were entering. Use a silicone or acrylic latex caulk for gaps around windows, doors, and baseboards. Acrylic latex is easier to work with because it cleans up with water and can be painted over. For larger openings where pipes or wires enter the wall, expandable foam, steel wool, or copper mesh will fill the space.
Clean out any peeling old caulk before applying new material so it adheres properly. Run a bead along the gap, then smooth it with a damp finger or rag. Don’t forget the bottom edge of door thresholds, which is one of the most overlooked entry points for small ants. Clear caulk is more forgiving than colored versions since mistakes are less visible.
Know What You’re Dealing With
Most room invasions involve one of a few common species, and identifying yours helps you respond appropriately.
- Odorous house ants are the most common indoor invader, about the size of a pinhead, brown to dark brown. Crush one and it smells like rotten coconut. They nest inside wall voids and under floors near moisture sources, and they respond well to sweet liquid baits.
- Pavement ants are reddish-brown to black, about 1/8 inch long, and usually enter from ground-level cracks. They eat both sweets and grease.
- Pharaoh ants are tiny (1/16 inch), light yellow to red, and nest exclusively indoors in northern climates. They’re one of the harder species to eliminate because colonies split when disturbed by sprays. Baiting is essential, and spraying can make the problem worse.
- Carpenter ants are much larger, up to 1/2 inch, black or black-and-red. They don’t eat wood but hollow it out for nesting. If you see small piles of sawdust-like shavings near baseboards or hear faint rustling inside walls, you likely have carpenter ants, and they need professional attention because the structural damage compounds over time.
Safe Options Around Kids and Pets
If you have young children or pets in the room, keep bait stations in locations they can’t reach: behind furniture, inside closets, or in enclosed bait traps rather than open gel. The vinegar-and-water spray is completely nontoxic. Plant-based repellent sprays using peppermint or cedarwood oil offer another low-risk option. These won’t eliminate a colony the way bait does, but they can help deter ants from specific areas like a crib or pet bed while the bait does its work elsewhere.
When DIY Methods Aren’t Enough
A few warning signs suggest the infestation is beyond what cleaning and baiting can handle. If ants spread across multiple rooms despite treatment, you’re likely dealing with a large or multi-nest colony that requires targeted professional treatment. If trails keep reappearing in the same spots after a week or two of consistent baiting, the nest location may be somewhere your bait isn’t reaching. Sawdust-like debris, hollow-sounding wood, or soft and damaged wood surfaces point to carpenter ants actively damaging your home’s structure, and both the ants and the underlying moisture problem need to be addressed. In any of these cases, a pest control professional can identify the species, locate hidden nests, and apply treatments that reach places consumer products can’t.