Sow Bugs

• WHAT YOU SEE

A cluster of small, gray, armored bugs under a flowerpot, a stack of firewood, or along the foundation where the ground stays damp. They move slowly and don't scatter the way ants or crickets do. Most people find them outside; indoors they usually mean a damp basement or crawl space corner.

• WHAT WE SEE

Sow bugs are crustaceans, not insects, related to shrimp and crabs more than to anything else on this list, and they breathe through gill-like structures that only work in damp air. That's why they never stray far from moisture: mulch beds, under stones, damp firewood, a basement corner with standing water at the sump. Unlike a pillbug, a sow bug can't roll itself into a tight ball, which is one of the quicker ways to tell the two apart in the field. A cluster of them is really a moisture reading on that specific spot, not an infestation in the structural sense.

• HOW WE FIX IT

The quarterly perimeter barrier and the general foundation cleanup, pulling mulch back from the siding, addressing a downspout that's draining against the wall, does most of the work here. Indoors, we treat the damp basement corner directly and point out the moisture source, since sow bugs won't stay somewhere that dries out. They're not a pest that needs aggressive treatment, mostly exclusion and a drier environment. Free re-service applies if they turn up again before the next visit.

• WHEN THEY SHOW UP

Sow bugs are most active in spring and after summer rain, when their outdoor habitat stays wet longest. They slow down and move deeper into soil and mulch once it turns cold. The foundation is where the population lives outside; the basement is the room they turn up in when they do come inside.

• WHAT THE PROS KNOW

Sow bugs are crustaceans, not insects, closer relatives of shrimp than of ants. Unlike a pillbug, a sow bug cannot roll itself into a ball, which is the quickest way to tell the two apart.