7 Signs of Termites in an Illinois Home

The seven signs to check

Walk the foundation, basement and sills and look for these:

• Mud tubes — pencil-width tunnels of soil running up the foundation or walls.
• Hollow-sounding wood — tap suspect trim and framing; a papery, hollow note signals internal damage.
• Discarded wings — small piles of equal-length wings on sills and near light.
• Swarmers indoors — winged reproductives near windows in spring.
• Frass — tiny wood-colored pellets (more common with drywood termites, but worth noting).
• Bubbling or blistering paint — can hint at moisture and termite activity just under the surface.
• Stuck windows or doors — warping from moisture and damaged wood can make them bind.

What are mud tubes, exactly?

Mud tubes are the single most recognizable sign of subterranean termites, the species that matters in northern Illinois. The termites build these soil tunnels to travel between the moist ground and the wood they feed on while staying hidden and humid. You will find them on foundation walls, around plumbing penetrations, and in crawl spaces.

A tube does not always mean an active colony — break a small section and check a few days later for repair, which indicates live termites. If you are unsure, leave it for an inspector.

Why spring is the season to look

Subterranean colonies release winged swarmers in spring, so that is when activity becomes visible to homeowners who otherwise never see the termites at work. Spotting swarmers or fresh wings indoors in spring is a strong reason to schedule an inspection rather than wait.

In older Joliet and New Lenox homes with wood near soil, damp crawl spaces or past moisture problems, the risk is higher and the signs are worth checking every year.

What to do if you find a sign

Do not disturb the area more than needed and avoid spraying, which can scatter activity and complicate an inspection. Confirming the species and extent is what determines the right treatment — a liquid soil barrier, in-ground bait stations, or both. The earlier you catch it, the less wood is lost and the simpler the fix.