Sweep or vacuum strays, compare dated sightings and correct actual moisture or access problems. Preserve useful outdoor populations; a whole-yard spray is not the default response.
To get rid of pillbugs and sowbugs indoors, sweep or vacuum the animals you see, then check damp shelter and entry gaps near that room. These land-dwelling crustaceans are usually incidental visitors. Repeated sightings call for inspection and moisture correction, not automatic spraying of the whole yard.
What Are These Little Gray Bugs?
Pillbugs and sowbugs are not insects. They are land-dwelling crustaceans called isopods. According to University of Florida extension entomologists, both are about 1/2 inch long and slate-gray. Their backs look like overlapping armored plates.
You can tell them apart with a quick look:
- Pillbugs (“rolly-pollies”) have no tail-like parts and roll into a tight ball when disturbed.
- Sowbugs (often called woodlice) have two small tail-like parts at the rear and can’t roll into a ball.
Both feed mainly on decaying plant matter. Indoors, they don’t damage your home, furniture, or food. They’re a nuisance, not a threat. That changes the goal. You don’t need a heavy treatment plan. You need a cleanup and moisture plan.
Other moisture-loving crawlers often turn up in the same garage or bathroom, and the two most common are centipedes and millipedes. In a centipede vs. millipede comparison, centipedes are flat, fast predators with one pair of legs on most body segments. Millipedes are slow and rounded, with two pairs of legs on most segments. They also coil up when disturbed and feed on decaying plants, much like pillbugs. Our guide to centipede vs. millipede identification compares their body shape, speed, and habits. It also covers household steps that help keep both pests out.
Why Do Sowbugs and Pillbugs Wander Inside?
These animals need high moisture to survive, and they’re most active at night. During the day, they rest under rocks, boards, trash, or rotting leaves. Some rest just below the soil surface.
Most indoor sightings start outdoors. University of Florida researchers note that a heavy indoor infestation usually signals a large population just outside. Mulch beds, grass clippings, and leaf litter against the foundation give them food and shelter. From there, a few crawl under a door sweep or through a gap.
In Florida, they can breed year-round. As a result, a busy flower bed by your back door can keep sending stragglers inside. A damp basement, crawl space, or constantly wet corner gives them a better chance of lasting indoors.
Keep one thing in mind. A pillbug inside doesn’t prove you have a leak or water damage. Sometimes one simply wandered in from wet soil after a rainstorm. Still, repeated sightings in the same room deserve a closer look.
Step 1: Remove the Ones You Can See
Start with the simplest fix. The UF/IFAS fact sheet recommends basic mechanical control for indoor sowbugs and pillbugs.
- Sweep them up with a broom and dustpan.
- Vacuum along baseboards, door thresholds, and corners.
- Empty the vacuum canister or bag outside afterward.
For a few stragglers, this may be all you need. There’s no reason to spray living areas for a pest that causes no indoor damage.
Step 2: Map Where and When They Show Up
Next, spend a week tracking your sightings. This quick step tells you where to focus your effort.
Keep a simple note on your phone. Record the date, the room, and the exact spot. Also note the weather, since sightings often rise after heavy rain or irrigation.
Look for patterns like these:
- Bugs clustered near one exterior door or a sliding glass track
- Activity along a garage-to-house entry
- Sightings near a bathroom, laundry area, or water heater
- Bugs appearing beside indoor potted plants
A cluster near one door is a reason to inspect its sweep and nearby shelter. In a damp room, check actual moisture conditions; near plants, inspect the pot and saucer. That map turns a vague annoyance into a short, specific to-do list.
Step 3: Dry Out Damp Spots Near Your Home
Moisture is the main reason these crustaceans hang around. Reducing it is one of the most useful long-term steps you can take.
Indoors, check the spots your map flagged. Look under sinks, behind washers, and around water heaters for slow drips. Run a bathroom fan during and after showers. Use a dehumidifier in a damp basement or utility room. Wipe up standing water around shower doors and laundry sinks.
Excess water draws in many pests besides isopods, so these fixes help your whole home. Gutters that overflow, soil that slopes toward the house, and humid crawl spaces all keep foundations wet. Our article on moisture control to keep pests out walks through gutters, grading, crawl space humidity, and leak checks in more detail. Those repairs also protect the structure itself from long-term damage.
A drier home won’t guarantee you’ll never see another pillbug. However, it makes your house a much less inviting place for them.
Step 4: Manage Damp Cover Close to the Foundation
You don’t need to wipe out every pillbug in your yard. Outdoors, these animals help break down dead leaves and plant matter. The goal is to move their favorite habitat away from your walls.
Focus on the first few feet around your foundation:
- Check mulch condition: Avoid deep, persistently wet mulch near walls; depth alone does not guarantee that it will dry.
- Pull mulch back: Leave a little space between mulch and the foundation, especially near doors.
- Move compost piles: Relocate compost and decaying vegetation away from the house.
- Clear leaf litter: Rake out leaves and grass clippings that build up against walls.
- Lift stored items: Move boards, bricks, and clutter that sit on damp soil near entries.
- Adjust sprinklers: Aim them so they don’t soak the foundation or doorways.
Once their shelter sits farther from the house, fewer of them will reach your door at night. Your garden beds can still hold a healthy population, just not one parked at your threshold.
Step 5: Close Up the Gaps They Use
Now return to your sighting map and seal the spots where bugs seem to enter. Isopods crawl slowly along the ground, so low gaps matter most.
Check these common entry points:
- Worn or missing door sweeps
- Gaps under garage doors and garage-to-house doors
- Cracked or missing weatherstripping
- Open spaces where pipes or wires enter the wall
- Cracks along slab edges and baseboards on exterior walls
Replace worn door sweeps and weatherstripping. Seal small cracks with a caulk that suits the surface. Seal only unintended gaps; do not block required vents, drainage openings or equipment clearances. It also helps block other crawlers that follow the same damp paths.
Homeowners often find centipedes in the same damp spots as pillbugs. Centipedes are predators that feed mainly on insects and spiders. They also favor humid closets and bathrooms, so a damp corner can host both. If you’re seeing more of them lately, our guide on why centipedes show up in your house explains common causes. It also covers how to make those areas less attractive.
Step 6: Check Potted Plants Before Bringing Them In
Potted plants offer an easy ride indoors. Damp potting soil and decaying leaves are exactly what pillbugs and sowbugs like. UF/IFAS specifically advises checking potted plants before moving them inside.
Before you bring a plant in:
- Lift the pot and check the bottom and drainage holes.
- Look inside the saucer, where water and debris collect.
- Remove dead leaves from the soil surface.
- Follow the plant’s watering needs and avoid persistently waterlogged soil.
For plants already inside, avoid overwatering. Empty saucers so water doesn’t sit for days. If bugs keep turning up beside one plant, take a closer look at that pot and its soil.
When Is Treatment Worth Considering for Pillbugs?
After you make these changes, keep tracking sightings for a few weeks. Compare the pattern with your earlier notes to see whether the changes are helping.
If the bugs keep coming, ask what changed. A new leak, heavy rain, or fresh mulch can bring a new wave. Then revisit the matching step above.
UF/IFAS notes that insecticides can be used as targeted crack-and-crevice or spot treatments where these pests enter. However, the same source says chemical control should come after you remove breeding sites and shelter. Treatment is not the starting point. Broadcast spraying across your yard isn’t a sensible default for a harmless nuisance. If you do consider any product, read and follow the label exactly. For a stubborn or confusing problem, a licensed pest professional can help track down the source.
Source: Pillbugs, Sowbugs, Centipedes, Millipedes, and Earwigs, UF/IFAS Extension (ENY-221/IG093)
Frequently Asked Questions
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Do pillbugs and sowbugs damage the house?
UF/IFAS describes them as indoor nuisance visitors that cause no structural damage. They feed mainly on decaying plant matter outdoors. This is not a pet-ingestion safety assessment; ask a veterinarian about an animal that has symptoms after eating an unidentified creature.
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Do pillbugs and sowbugs mean I have a water leak?
Not always. A single pillbug can wander in from wet soil after rain. However, repeated sightings in one room are a good reason to check for leaks, condensation, or high humidity nearby.
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Can sowbugs and pillbugs live inside my house?
They need high moisture, so dry living spaces don't suit them. A damp basement, crawl space, or wet corner gives them a better chance. A steady stream indoors usually means a large population is living just outside.
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Should I spray my whole yard to get rid of them?
Usually not. Outdoors, these isopods help break down dead plant matter. It works better to thin mulch, move damp debris away from the foundation, and seal entry gaps. Any treatment should be targeted and follow the product label.
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Why do I see more pillbugs after it rains?
Heavy rain soaks the soil and their resting spots. As a result, they may move toward patios, garages, and doorways. Sightings often drop again once things dry out.
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What's the easiest way to remove pillbugs I find indoors?
A broom and dustpan or a vacuum works well. Empty the vacuum outside afterward. For a few stragglers, that may be all you need while you work on moisture and entry points.
Vincent founded On Demand Pest Control in 2017 and is a Florida Certified Operator in all four state categories. He treats pest control as a systematic problem to solve, not a symptom to spray. Read Vincent’s full bio →
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