">
Household ant close-up

Field Guide · Herbal Shield

Household Ants
Monomorium pharaonis & Tapinoma sessile

Small, persistent, and highly social — ant colonies require colony-kill strategies, not surface spraying. Our borax-bait-first approach eliminates the source without exposing your family to harsh chemicals.

Borax BaitFood-Grade DEBotanical SprayColony Kill
Care Card
Identification & Behavior
Ant
Pharaoh Ants
Very small (1–2mm), pale yellow to reddish-brown. Nest inside walls, behind baseboards, and near warm, moist areas like kitchens. Massive colonies that split when stressed — never spray directly, it accelerates colony spread.
Odorous House Ants
Small (2–3mm), dark brown/black. Emit a rotten-coconut smell when crushed. Nest outdoors but forage aggressively indoors for sweets and grease. Common along window sills, under sinks, and near trash.
Signs of Activity
Live trails along counters, baseboards, and pipe runs. Small soil piles near entry points. Concentrated foraging around food sources or moisture. Most active spring–fall, but Pharaoh ants are year-round indoors.
Why They Enter
Food crumbs, pet food, open recyclables, moisture from leaks. Honeydew-producing insects (aphids, scale) on exterior plants also attract ants. Closing food sources is more effective than any treatment alone.
Pressure Indicators

Field call: how much pest pressure is on the property. Determines urgency, treatment intensity, and whether botanical alone is enough or whether escalation-consent should be discussed.

Low
Occasional foragers, single trail, one room.
Moderate
Multiple trails, kitchen + one other room, active recruitment.
Heavy
Swarm satellite colonies, structural voids, budding suspected — consider escalation-consent if 3+ visits fail.
IPM Action Steps
1
Identify the Species
Size, color, and trail behavior determine your approach. Pharaoh ants require bait-only — spraying causes budding. Odorous house ants respond to both bait and botanical sprays at entry points.
2
Set Thresholds
An occasional stray ant near an entry point may not need treatment. A defined trail into food storage or contamination of food always warrants action.
3
Sanitation & Exclusion First
Seal all entry points with silicone caulk. Store food in airtight containers. Dispose of trash daily. Clean pet food bowls. Wipe down counters and rinse recyclables before binning.
4
Place Monitoring Traps
Install sticky traps near suspected entry points and along baseboards. Check every 48 hours. Map trail paths before treatment — this determines bait station placement.
5
Mechanical Controls
Vacuum active trails. Wipe trail pheromones with soapy water to disrupt navigation. Apply boiling water directly to any outdoor nest if accessible.
6
Targeted Least-Toxic Treatment
Place borax bait stations along active trails without disturbing them. Apply food-grade DE or silica gel dust in cracks, voids, and behind appliances. Use botanical spray at exterior entry points only — not on active indoor trails.
7
Evaluate & Follow Up
Check bait stations every 3–4 days. Refresh liquid bait when dry or depleted. Expect activity to increase for 3–5 days before declining — this is normal. Full colony resolution typically takes 1–2 weeks.
Prevention & Cultural Controls
Exclusion
Seal gaps around pipes, windows, and door frames with silicone caulk. Install door sweeps. Check and repair window screen tears. Caulk the backsplash-counter gap — a common entry hidden in plain sight.
Sanitation
Clean counters nightly. Store all food in sealed glass or hard plastic. Empty indoor trash daily. Rinse recyclables before binning. Keep pet food in sealed containers and wash bowls after feeding.
Landscaping
Trim vegetation away from the foundation — 12+ inches clearance. Remove aphid-infested plants or treat aphids (they produce honeydew ants harvest). Keep mulch depth below 3 inches near the foundation.
Application Techniques
Borax Liquid Bait — The Primary Tool for Most Ants
  1. Place bait stations directly on active trails — do not move them once placed.
  2. Use 2–4 stations per trail, spaced 18–24 inches apart along the foraging path.
  3. For Terro stations: break the tab at the score line and lay flat near the trail.
  4. Do NOT spray near bait — it repels ants and prevents colony kill.
  5. Expect increased activity for 3–5 days as ants recruit heavily to the food source. This is the bait working.
  6. Refresh liquid bait every 3–5 days or when depleted.
  7. Remove stations and wipe with soapy water after activity stops completely.
Diatomaceous Earth & Silica Gel — Cracks & Voids
  1. Use a bellows duster to apply a thin, barely-visible film — heavy piles are counterproductive and waste product.
  2. Target: inside wall voids, behind outlet covers, under appliances, inside cabinet toe kicks.
  3. Keep dry — DE loses effectiveness when wet. Never apply in areas where moisture accumulates.
  4. Reapply after cleaning or if area gets wet.
  5. Vacuum excess after 10–14 days once activity has stopped.
Botanical Sprays — Exterior Entry Points Only
  1. Apply peppermint, cedar, or orange oil spray at exterior entry points only — window frames, door frames, foundation crack lines.
  2. Never spray directly on active indoor trails — it disperses the colony.
  3. Reapply every 5–7 days outdoors, or after rain.
  4. Shake bottle well before use. Apply to a small inconspicuous area first to test for surface staining.
Recommended Products
Terro Liquid Ant Baits
Borax-based liquid bait. Pre-filled stations with scored tab for easy opening. Primary colony-kill tool for odorous house ants and most household species. Allow 1–2 weeks for full effect.
Borax / Colony Kill
Mighty Mint Peppermint Oil Spray
Concentrated peppermint oil in water base. Use at exterior entry points and as a perimeter deterrent. Pleasant scent, safe for families and pets once dry. Reapply weekly or after rain.
Botanical / Repellent
Orange Guard (d-Limonene)
Citrus-derived d-limonene spray. Kills on contact and repels. Safe around food prep areas and pets when dry. Use at exterior points and along foundation lines. Not for active indoor trails.
d-Limonene / Contact Kill
Harris Food-Grade Diatomaceous Earth
Food-grade DE with powder duster. Apply thin layers in cracks, voids, and behind appliances. Physically damages ant exoskeletons without chemical toxicity. Effective as a long-term crack-and-crevice barrier.
Food-Grade DE / Mechanical
▶Training Videos
Bait Application
Terro PCO Liquid Ant Bait Stations — DIY Tutorial
Breaking the tab, placing stations along trails, avoiding disturbance, and understanding the colony-kill timeline.
▶ Watch on YouTube
Ant
Bait Placement
How to Use Terro Ant Bait Traps
Step-by-step placement, refresh timing, and following the trail to identify optimal station locations.
▶ Watch on YouTube
Dust Application
Diatomaceous Earth — Indoor Crack & Crevice Technique
Bellows duster technique, thin-layer application into cracks and voids, keeping product dry, and when to reapply.
Search: Harris Diatomaceous Earth Application Tutorial
Botanical Spray
Mighty Mint Peppermint Oil — Ant Control Demo
Spray technique along entry points and baseboards. How essential oils disrupt ant navigation and deter future foraging.
Search: Mighty Mint Peppermint Oil Ant Control Demo
Warnings & Herbal Shield Standards
Increased Activity is Normal: Bait stations will attract more ants for the first 3–5 days. This means the bait is working. Never remove stations or apply spray during this phase — it breaks the colony-kill cycle.
Never Use Neurotoxic Sprays: Bifenthrin, pyrethrins, and similar contact insecticides repel and scatter colonies without killing the queen. This makes problems harder to resolve and is inconsistent with Herbal Shield's least-toxic brand promise.
Food-Grade DE Only: Always use food-grade diatomaceous earth — never pool-grade (calcined) DE, which is hazardous to inhale. Wear a dust mask during application. Keep away from children until settled.
Client Script: "We're placing a small amount of borax-based bait along the trail — the ants will carry it back to the colony. You may see more activity for a few days, which is the bait working. The colony should resolve within 1–2 weeks without any spraying in your living space."
Client Script — Why Bait, Not Spray: "The reason we use bait stations instead of spraying is that these ants have massive colonies — sometimes tens of thousands of workers. If we spray and kill the foragers you see, the colony just produces more. When we use bait, the workers carry it back to the colony and share it through feeding — that's what actually collapses the nest. You'll see more ants for 3–5 days as they recruit to the food source, but that means it's working. Within 1–2 weeks, you should see a clear decline."

Have household ants in your Maryland home?

Call and walk us through what you're seeing. We'll tell you what we can treat, what we can't, and what it costs — and if it falls outside our license, we'll say so and point you to someone who holds it.

Call (443) 228-6070 Request a callback

Greater Baltimore & the DC-metro counties · MDA Categories 7A + 7D licensed · what we do & don't do