Pill bug

Adult pill bug (Joseph Berger,

Pill bug

Adult pill bugs (Gary Alpert, Harvard University,

Pill bugs

Pill bugs of various sizes (Wikimedia Commons)


  • also known as sowbugs or pillbugs
  • range from 1/4 to 5/8 inch long
  • dark to slate gray
  • oval, segmented, armored bodies
  • can roll up into a tight ball when disturbed

Nesting Habits

  • many habitats including moist soil, leaves, grass, wood piles, mulch and stones
  • require high moisture
  • come indoors when moist conditions exist


  • decaying organic material


  • occasionally come indoors under thresholds/doors
  • may be a nuisance indoors

IPM Recommendations

  • Minimize moisture and hiding/feeding areas near the foundation.
  • Seal cracks around the outside foundation wall.
  • Install tight-fitting door sweeps at the base of all exterior doors.
  • Vacuum individuals that enter buildings.