Dr. Killigan's guide to household insect problems

Dr. Killigan's guide to household insect problems

Published May 16, 2022 • Updated October 17, 2025
Reviewed by Julie Miller, BA in Language Arts, Editorial Lead, Dr. Killigan’s

TL;DR: seal entry points, remove food and water sources, store dry goods sealed, reduce clutter, set target-specific traps and use plant-powered contact sprays for spot kill. 

In this guide: Cockroaches • Ants • Flies • Mosquitoes • Pantry moths • Clothing moths • Fruit flies • Spiders

They may be breeding on the produce that you walk through your front door with, slipping in unnoticed when the screen door swings open in the wind, crawling in through a crack in your foundation or already wiggling around in that box of pasta. Either way, you want these bugs handled—quickly and cleanly.

Fear not: Dr. Killigan is here to help with pest knowledge and understanding, tips, solutions and infestation advice. Consider this Insect Combat 101—your guide to insect problems plaguing households near and far.

Cockroaches

If a roach darts under the fridge, it’s time to act. Here’s how to get rid of cockroaches in the house—fast and for good.

[Common household species include German, American, brown-banded, smoky brown and Oriental cockroaches.]

Act on food, water and shelter first. These pests hide in tight, warm crevices and thrive where crumbs and leaks persist. The fastest way to get rid of cockroaches in the house is a cleanup + sealing + targeted treatment combo.

Do:

  • Declutter kitchens and storage; remove cardboard stacks and paper bags
  • Store food sealed; wipe crumbs and grease from counters, appliances and floors
  • Fix leaks and drips under sinks and at fridge lines; dry sink rims and disposal collars
  • Seal cracks and gaps at baseboards, pipe penetrations and cabinet joints
  • Vacuum along wall—floor seams and inside cabinet corners

Why:
Roaches follow moisture, food residues and tight shelter. Oothecae (egg cases) hatch in protected crevices, so removing water and access points breaks the cycle and reduces rebound.

Did you know: roaches defecate near food and nesting sites; pepper-like droppings in dark, tight crevices are early signs.

Monitor:

  • Check weekly for pepper-like droppings, egg cases and shed skins behind and under appliances and sinks

Treat:

cockroach on rock

Common hideouts to check: behind or under refrigerators and stoves, under sinks and around plumbing penetrations, inside cabinet corners, drawers and pantry shelves, under small warm appliances like toasters and coffeemakers, along baseboards and wall—floor seams, in storage areas with cardboard or paper bags and around drains, pipes and faucet leaks.

Further reading: How to quickly get rid of American and German cockroaches ↗ ·  How to get rid of cockroaches

Ants

Black ant on leaf

When a line of ants cuts across the counter, don’t let it spread. Here’s how to get rid of ants in the house and stop them from coming back.

[Common household species include Argentine, odorous house, pavement and carpenter ants.]

Do:

  • Wipe crumbs and sweet or oily residues from counters, floors and appliances
  • Store food sealed; empty trash and rinse recyclables
  • Fix drips at sink, dishwasher and fridge lines; dry sink rims and disposal collars
  • Seal entry gaps at baseboards, window tracks, door thresholds and pipe penetrations

Why:
Foragers leave outdoor nests to exploit steady food and moisture indoors. If crumbs or leaks persist, recruitment restarts within hours. Removing residues, drying leaks and closing entry points breaks the loop and prevents rebound.

Did you know: many nuisance ants (e.g., Argentine, odorous house ants) build multi-queen “supercolonies,” so trails can reappear from several satellite nests. That’s why sanitation and sealing matter as much as spot kill.

Monitor:

  • Check daily for new trails along baseboards, backsplashes and under appliances
  • Note where trails start and end; refresh Six Feet Under at those points if activity returns. Reapply sooner after deep cleaning or heavy moisture.
  • Reduce moisture hotspots under the sink and around pet bowls

Treat:

  • Use Six Feet Under—plant-powered contact kill with clove & cinnamon oils; residual protection up to 30 days (reapply after deep cleaning or moisture).
  • In cracks and tight seams where ants enter, apply Dust to Dust with the Insect Buster in thin, targeted lines as directed

Optional helper: a light wipe of peppermint or clove oil at door thresholds can discourage scouting ants. 

Common hideouts to check: along baseboards and wall—floor seams, under sinks and around plumbing penetrations, behind or under refrigerators and dishwashers, inside cabinet corners and pantry shelves, at door thresholds and window tracks and where exterior trails enter the kitchen or bath.

Learn more: How to get rid of ants ↗ ·  How to repel ants with essential oils

Flies

fly

If flies cluster by the window or hover over the sink, it’s time to clear the air. Here’s how to get rid of flies in the house naturally and effectively.

[Common household culprits include house flies and drain flies; both follow light and food residues.]

Do:

  • Keep indoor trash cans closed and clean; wipe sticky residues on counters, floors and appliances
  • Deep-clean drains and disposals; rinse recyclables and bottles
  • Install tight screens and repair tears; keep doors closed or use a screen door
  • Place The Fly Inn along the lower edge of busy windows; its shielded design keeps catches out of sight 
  • Store produce covered or refrigerated; empty compost caddies often 
  • Seal pet food in lidded containers and clean bowls nightly
  • Keep outdoor bins closed, clean pet areas and maintain compost properly to limit breeding nearby

Why:
Flies breed where fermenting food, damp organics and film build up. Light and airflow patterns draw adults to windows and glass doors; drains and trash provide ongoing sources if not cleaned. Outdoors, common sources include compost, pet waste and manure; managing these reduces indoor pressure.

Did you know: many flies are positively phototactic—they head toward light. We use this attraction to draw flies into The Fly Inn. 

Monitor:

  • Check window sills and near lights daily for landings and new activity 
  • Inspect sink rims, overflows and drain covers weekly for organic film
  • Replace or reposition The Fly Inn if catches slow; adjust toward the brightest window and away from competing lights 

Treat:

  • For visible flies, use Six Feet Under for contact-kill
  • For drain flies, scrub inside the drain walls with a brush and flush with hot water after using a suitable cleaner; repeat until activity stops
  • Maintain traps; replace when full  

Common hideouts to check: sunlit windows and glass doors, around trash and recycling lids, sink rims and disposals, floor drains, under appliance kickplates, compost caddies and sticky spill zones, plus nighttime resting spots on ceilings, walls and curtains.

Further reading: What attracts flies and the colors they’re drawn to↗ ·  How to get rid of flies in your house (the right way)

Mosquitoes

mosquito

When mosquitoes swarm at dusk on the patio, you need quick relief. Here’s how to get rid of mosquitoes around the house and reclaim your evenings.

[Common backyard culprits include container-breeding mosquitoes that use small pockets of standing water.]

Do:

  • Dump standing water every 3-4 days: buckets, plant saucers, toys, tarps, wheelbarrows, grill covers
  • Clear gutters and downspouts so water doesn’t pool
  • Refresh birdbaths and pet bowls frequently; store watering cans upside down
  • Fix yard drainage low spots; level or fill dips that collect water 
  • Screen rain barrels with fine mesh and keep lids tight
  • Cover hot tubs and pools; drain water off pool covers
  • Snap trash-can lids tight; rinse sticky residue
  • Install tight window and door screens; repair tears and add door sweeps
  • Use fans where you sit outdoors to disrupt flight near people 

Why:
Mosquitoes lay eggs on or near still water. A small amount left for several days can support larvae. Removing water stops breeding at the source and screens reduce entry. After storms, floodwater species hatch in waterlogged soil and low spots—drain and dry those areas promptly.

Did you know: many mosquitoes stay close to where they hatch—removing standing water on your property reduces bites fast.

Monitor:

  • Do a weekly yard walk after rain and tip or toss anything holding water
  • Check gutters, drain trays, plant saucers and shaded corners that stay damp
  • Note peak times (usually dusk) and locations to target your efforts

Treat:

  • For visible mosquitoes, use Six Feet Under for contact-kill; avoid spraying in breezy conditions and around pollinator-attractive blooms 
  • Use fans during outdoor time to keep mosquitoes away from seating areas

Common hideouts to check: plant saucers and tray bottoms, clogged gutters and downspouts, buckets and toys left outdoors, tarps and grill covers that hold puddles, old tires, wheelbarrows, open rain barrels without screens, landscape low spots and dense, shaded vegetation near damp soil.

Learn more: How weather affects flies and mosquitoes ↗ ·  Mosquitoes: More than just pests—surprising ecological benefits revealed

Pantry Moths

If tiny moths flutter near your shelves or dry goods, act fast. Here’s how to get rid of pantry moths and protect your food stores.

[Common household species: Indian meal moth (pantry moth) and related pantry moths like Mediterranean flour moth and almond moth.]

Do:

  • Inspect all dry goods for webbing or larvae; check seams of bags and boxes, under lids, corners of shelves
  • Check edges of cans and spice jars, inside lid threads and even unopened packages for hidden larvae
  • Toss heavily infested items; for questionable items, freeze 48–72 hours in sealed bags to stop hidden stages
  • Vacuum shelves, crevices and shelf-pin holes; wipe with warm soapy water or vinegar and let dry fully
  • Store flour, grains, cereal, nuts, seeds, baking mixes and pet food in airtight, hard-sided containers
  • Place Dr. Killigan’s Pantry Moth Traps (2–3 per area)—trusted by 300,000+ households; Blue Stripe pheromone targets males; insecticide-free mechanical capture.

Why
Larvae develop inside packages and spill zones. Thin plastic and cardboard don’t stop them, so decanting to hard-sided airtight containers removes access to food. Pheromone traps remove males from the population, reducing mating and driving numbers down over the life cycle.

Did you know: most pantry moth problems ride in with packaged dry goods. Quick inspections on grocery day prevent weeks of cleanup.

pantry moth

Monitor:

  • Check Pantry Moth Traps weekly and replace when full
  • Reinspect shelves and container lids for new webbing or clumped food
  • Quarantine new dry goods in sealed bins for 2 weeks or decant into containers on day one

Treat:

  • For visible moths or larvae on surfaces, use Six Feet Under for contact-kill
  • Repeat the clean-inspect-trap routine for several weeks to cover egg-to-adult timing 

Common hideouts to check: flour and cereal bags, rice and grain bins, nuts and seeds, baking mixes, dried pet food and birdseed, shelf corners, under shelf liners, inside shelf-pin holes, inside lid threads and bag folds

Learn more: How long does it take to get rid of pantry moths↗ ·  Beyond breadcrumbs: 7 unexpected places you might find pantry moths↗ ·  Will eating a pantry moth make you sick?

Clothing Moths

clothing moth

Notice moths drifting from the closet or damage in your wool? Here’s how to get rid of clothing moths and prevent wardrobe damage.

[Common household species: webbing clothes moth and casemaking clothes moth.]

Do:

  • Launder or dry clean wool, silk, cashmere and blends before storage; let items dry fully 
  • For washable items, use hot water over 120°F or steam where fabric care allows
  • Declutter closets; vacuum floors, shelf edges, baseboards and corners 
  • Store off-season garments in airtight garment bags or sealed bins
  • Add Cedar Planks to closets and drawers—natural aroma helps deter adult clothes moths; refresh scent with Cedar Ward Cedar-Rejuvenating Spray or a light sanding when aroma fades. Use cedar alongside cleaning and traps, not as a stand-alone fix.
  • Move garments regularly; improve light and airflow so areas aren’t dark and undisturbed

Why:
Larvae feed on animal fibers rich in keratin—wool, silk, fur, feathers, felt and leather—especially where body oils, sweat or food stains linger. Clean fibers remove the attractant. 

Did you know: most damage happens under collars, cuffs and along seams where body oils collect. Cleaning before storage is the single best prevention step.

Tip: Cedar only works when it smells—if the aroma’s gone, it’s time to refresh or respray. Avoid direct contact with delicate light fabrics; place planks/sachets near (not on) garments.

Monitor:

  • Place Dr. Killigan's Clothing Moth Traps at closet entry and near storage bins—pheromone lure targets male clothes moths; insecticide-free, mechanical capture helps break the breeding cycle.
  • Look for silk-like webbing, sand-like frass and irregular threadbare patches on wool and silk
  • Recheck rarely worn items monthly, plus rug edges and under furniture slipcovers
  • Expect a lag: eggs laid today can hatch in 2—4 weeks, so keep traps out through a few life cycles

Treat:

  • Discard items with heavy, active infestation
  • Isolate affected garments; freeze in sealed bags 48—72 hours or dry clean per fabric care
  • Thoroughly vacuum closet floors, corners, shelf joints and baseboards; dispose of bag contents
  • Wipe hard surfaces, shelves and baseboards with warm soapy water, vinegar or Six Feet Under; let dry fully
  • Keep Clothing Moth Traps in place to capture males and track rebound over several weeks

Common hideouts to check: under collars and cuffs, seams and hems, inside pockets, wool throws and felts, stored furs, feather accessories, rug edges and under furniture, piano felt pads, animal-bristle brushes and undisturbed closet corners.

Tip: after sweaty workouts, don’t re-shelve garments—wash or air and clean first to remove the scents larvae follow.

Further reading: What’s eating my wool—carpet beetles or clothing moths?↗ ·  Pantry moths vs. clothing moths↗ ·  Do clothing moths actually eat clothes?↗ ·  Where do clothing moths come from?

Fruit Flies

Fruit fly

When fruit flies hover over the bowl or drain, don’t wait. Here’s how to get rid of fruit flies in the house and keep them from returning.

[Common household culprits: fruit flies that breed in fermenting produce and organic film in drains.]

Do:

  • Clear the food source: discard overripe produce and sticky spills on counters, floors and appliances
  • Store fruit covered or refrigerated; rinse bottles and recyclables before binning
  • Deep-clean drains and disposals: scrub the inner walls, then flush with hot water after a cleaner
  • Wash mop heads and dishcloths; empty compost caddies often and wipe lids 
  • Keep trash can lids snapped tight and the can interior clean 
  • Set Sweet Surrender Fruit Fly Trap—plant-based attractant that targets fermenting-fruit seekers; pour 2 oz per trap; reusable trap container with refills lasting up to 6 weeks (unopened refills store up to 2 years).  

    Why:
    Fruit flies breed in fermenting residues and damp organic film (overripe fruit, wine/beer spills, vinegar, trash “goo,” mop buckets, drain slime). Removing food sources and drain film breaks the lifecycle. Traps attract adults so populations crash while you clean. 

    Did you know: fruit flies lay eggs on moist, sugary surfaces—think banana stems, juice rings under bottles and film in sink overflows.

    Did you know: in warm conditions a female fruit fly can lay up to 2,000 eggs and go from egg to adult in about 2 days, so small residues quickly become swarms.

    Tip: fruit flies are often mistaken for gnats—gnats look more like tiny mosquitoes; fruit flies look like mini house flies.


    Monitor
    :

    • Check Sweet Surrender daily for the first 3 days, then 2—3x/week; replace when full, evaporated or at up to 6 weeks after opening
    • Watch fruit bowls, compost caddies, sink rims and drain overflows for new landings; reposition traps toward the most active spot
    • If flies persist but catches drop, refresh attractant and deep-clean drains/disposals, then reassess placement
    • Expect spikes after produce runs and in warm, humid late summer to early fall—keep an extra trap ready

    Treat:

    • For visible adults, use Six Feet Under for contact-kill
    • For drain flies, scrub inside drain walls and under stoppers to remove slime, then flush with hot water; repeat daily 3–5 days, then do weekly maintenance
    • Optional DIY drain clean: pour ½ cup baking soda + ½ cup salt into the drain, add 1 cup vinegar, wait 2 hours, flush with hot water

    Common hideouts to check: fruit bowls and produce drawers, sink rims and disposals, drain overflows, recycling bins and bottle crates, trash can lids and seams, compost caddies, mop buckets and sponge trays, sticky spill zones under small appliances.

    Further reading: Vinegar vs. fruit flies—what really works?↗ ·  Why are fruit flies so hard to get rid of?

    Spiders

    If webs appear in corners or a spider crosses the wall, take control. Here’s how to get rid of spiders in the house and keep them out.

    [Common household species include house spiders, cellar spiders, wolf spiders, jumping spiders]

    Do:

    • Vacuum ceiling corners, window sills, wall–ceiling junctions and baseboards; knock down indoor and outdoor webs
    • Reduce clutter in basements, garages and closets; store items in sealed bins instead of cardboard
    • Seal gaps at door sweeps, window frames and utility penetrations; repair screens
    • Swap bright exterior bulbs for warmer LEDs or motion lights and keep bright fixtures away from doors
    • Tidy outdoor zones: move firewood and debris off the house, trim vegetation off siding, clear cobwebs from eaves, locate compost/trash away from entries
    • Dry damp areas with ventilation or a dehumidifier; fix leaks under sinks and in crawl spaces
    Spider in web

    Why:
    Spiders follow shelter and prey. Bright lights and food residues attract insects (e.g., porch lights, crumbs, open bins), which attract spiders. Cluttered, undisturbed areas and moisture create ideal harborage. Sealing entry points and reducing prey pressure lowers spider activity indoors.

    Did you know: if you reduce the insects around lights and doors, spider activity usually drops within days.

    Did you know: a single spider egg sac can hold dozens to hundreds of eggs—vacuuming and discarding sacs is one of the fastest ways to cut future activity.

    Monitor:

    • Once a week, sweep for fresh webs and egg sacs in corners, window frames and storage areas
    • Note where spiders appear at night around porch lights and doorways; that’s where exterior cleanup matters most

    Treat:

    • For visible spiders, use Six Feet Under for contact-kill
    • After cleaning, apply Dust to Dust with the Insect Buster in thin lines along baseboards, garage thresholds, utility entry points and other travel seams as directed
    • Vacuum webs and egg sacs directly and discard the vacuum contents outdoors

    Common hideouts to check: ceiling corners and wall–ceiling seams, behind and under furniture, window and door frames, basements and crawl spaces, garages and storage rooms, exterior eaves and soffits, around porch lights and stacked firewood

    Learn more: Which spiders are living in my home?↗·  How long can spiders live without food?

      Julie standing outside with red shirt and blurred background

      Content Strategist & Eco-Living Advocate

      Julie Miller

      Julie is Dr. Killigan’s in-house writer and content strategist with a passion for science-backed, natural living. She holds a degree in Language Arts and brings over a decade of writing experience to the team. At Dr. Killigan’s, she works closely with the product and customer experience teams to ensure every article delivers accurate, helpful and trustworthy information. When she’s not writing, Julie is tending her vast array of indoor plants, crafting homemade moisturizers or fermenting carrots with her children.

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