How to Kill Pillbugs and Sowbugs

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Click on image to enlarge

(Photo: J. Kalisch
University of Lincoln
Nebraska Dept. of Entomology)

General Information

  • Pillbugs and sowbugs as pests are more closely related to shrimp and crayfish than to insects being of the class Crustacea.
  • The typical sowbug has two tail-lole appendages at the tip of the abdomen.
  • Sowbugs and Pill bugs are incapable of rolling into a tight ball.
  • The common pillbug doesn't have the appendages and are capable of rolling into a tight ball. They are often called "rolly-polies".
  • They live outdoors, feeding on decaying organic matter and occasionally young plants and their roots.
  • They may be found around flower bed mulches, grass clippings, leaf litter, rotting boards, trash, rocks and pet droppings are present.
  • Sowbugs and Pill bugs can be found invading damp basements and crawl spaces.
  • On a hot day, they remain under objects on the damp ground and are active only at night due to lower temperatures and more humid conditions.
  • On a hot day, they remain under objects on the damp ground and are active only at night due to lower temperatures and more humid conditions.
  • Sowbugs and Pill bugs may infest potted plants.
  • When the infestation is heavy, it generally indicates a large population immediately outside the building.
  • Adequate moisture is essential for their survival, and they group in masses to reduce water loss.
  • They become inactive during the winter months except in heated buildings such as greenhouses.


Prevention of Sowbugs and Pillbugs

  • Prevention begins outdoors by removing harbor aging places that hold moisture, such as wood debris, rocks, grass clippings, and leaf litter and other debris from the foundation walls, doors, basement windows and other points of entry.
  • Firewood should be stored off the ground.
  • Lawns should be watered in the morning to promote drying by the afternoon.
  • Flower beds should not be over mulched.
  • Properly ventilate basements and sub floor crawl spaces to eliminate excess moisture.
  • Repair and seal cracks and openings in the foundation wall, around doors, and around basement windows with caulking compound and weather stripping.
  • Drain standing water and moist areas near potential points of entry.

How to Kill /Control Pillbugs and Sowbugs

  • Use professional residual insecticides recommended below. Spray along entry points, cracks-crevices and along baseboards in important. Even more effective would be a good residual sprayed on the outside as a perimeter treatment along the exterior foundational walls.


    Lambdastar Ultracap 9.7

    lambdstar ultracap

    LambdaStar Ultracap 9.7 (Broader label and longer lasting-may be used inside or outside and will dry invisible. Lambdastar Ultracap has no smell. LambdaStar Ultracap will last longer outside and adhere to the surface better due to its encapuslated technology. It will yield 20-40 gallons

    cyper wsp

    Cyper WSP



    demon wp

    Demon WP

    Cyper WSP and Demon WP have the same label, but Cyper WSP is more economical.

    Demon WP and Cyper WSP will leave a visible residue seen against dark wood.

    Spray a perimeter treatment about 3 feet along the foundation and 3 ft. up the exterior wall. Also spray around the entry points like doors and windows. LambdaStar UltraCap 9.7 will not leave a visible residue seen on dark surfaces as Cyper WSP or Demon WP do.

    Repeat treatments of these suggested liquid residual insecticides every 3 months.

    In addition, use an aerosol like Micro Care Aerosol micro care aerosol Micro Care Pyrethrum, sprayed around doors and windows and other places where these pests may enter premises. This aerosol comes with a crack and crevice tip enabling you to spray into the smallest cracks and crevices.

    Repeat treatment of this aerosol once a month.

  • Granules:

    bifen granules Bifen LP Granules would be an additional treatment around the house to serve as a barrier against pillbugs or sowbugs. The advantage of granule treatments in addition to liquid residual barriers is that they hold up under rainfall.

    Repeat treatments of granules every 3 months