5 Signs of Structural Termite Damage

Written by Chem-Wise on . Posted in Blog

Spring is the season when termites in Illinois look for new spots to colonize. Subterranean and drywood are the main structural termite pest types in the Chicago area. Learn how to recognize termites and what the signs of a termite damage are.

What Do Termites Look Like?

These pests look similar to ants in both size and shape, but if you’re not sure if the bug you’re looking at is a termite, watch for:

  • Straight waists instead of pinched waists
  • Straight antennae instead of bent antennae
  • Discarded wings, since flying ants do not shed wings like termites do

However, you may never actually see termites, even if they infest your home. Learn the five signs of a structural termite infestation so you can catch an infestation quickly.

1. Swarms of Winged Reproductives

When it’s time to leave the nest and start a new colony, pairs made up of one male and one female swarm with their nursery-mates. Swarms vary in size from a few individuals to many thousands of winged reproductives.

The swarm moves with a shimmering grace. The insects are airy in appearance, and their wings fall off from a touch of your hand. You may see a swarm outside attracted to lights. Outdoor termites are not a definite sign of termite infestation, but may only be passing through and feeding local wildlife.

If you see swarms inside your house or you find shed wings on your windowsills and floors, that’s a bad sign. Swarming termites indoors are emerging from a colony indoors or under the foundation. Your home should be inspected for termites as soon as possible.

A random individual reproductive termite, or alate, is not a cause for alarm. It may have wandered in on a pet or the wind. A group of alates climbing the wall or flying up from a loose tile are a symptom of a serious structural termite infestation.

Don’t mistake swarming ants or other insects for termite reproductives. Termites and ants look similar when they swarm, but ants have narrow waists and elbowed antennae while termites are broad in the waist and have non-segmented antennae.

Mud Tubes

Mud tubes are another clear sign that your home has a termite problem. Subterranean termites create mud tubes to protect themselves from dry air and predators above ground. As their name suggests, subterranean termites live underground in vast colonies with up to one million individuals.

Subterranean termites are hard to notice because of their below-ground habitat. Nests may extend several feet below ground level before a homeowner notices the infestation. Subterranean termites avoid drying out by colonizing in moist soil in crawl spaces, under foundations, and next to basements.

Mud tubes are constructed by worker termites to provide safe passage from the underground colony up into the wood in your floor joists, sill plates, subfloor, and framing. Mud tubes can be:

  • Sand-colored
  • Gray
  • Charcoal
  • Red-clay-colored

Mud tubes can also be a mixture of colors if there are several soil types around your home.

Subterranean termites forage up to 150 feet away from their colony. Tubes may extend to upper floors or toward attached buildings.

Look for mud tubes on the side of your home and inside your basement if it has a dirt floor. Check for mud tubes along the foundation, crawl space, or slab. Subterranean termites also take advantage of cracks in cement or concrete as small as 1/32 inch to access wood in your home.

Wood Issues

If structural wood, including any studs, joists, or framing, begins to crumble in spots, look beneath the surface of the wood for evidence of tunneling, larvae, and packed dirt. Drywood termites may have invaded a section or a dozen sections of wood in your home.

Subterranean and drywood termites are very sneaky about their consumption of your wood. They try to keep the outside of a board looking normal while they tunnel through the wood just under the outer grain. Termites may cause blistering and warping just under the surface of wood, too.


When drywood termites infest furniture or flooring, they push tiny pellets out of the tunnels they create in wood. These wood-colored or blackish pellets are called frass and may be found in small mounds under dressers, wooden chairs, or flooring.

If you look closely, you’ll see that each piece of frass has six sides. These pellets are what’s left of the wood the termites have digested. The termites push them out of tiny holes when they clean their nests. Where you find one pile of frass, you may find dozens more scattered around your home.

Hollow Sound

Be suspicious of any structural wood that sounds hollow when you knock on the surface. That hollow sound is a clear indication of pest damage or other structural issues. Wood should sound solid and make a dull thud when knocked.

If you’re curious, you can poke a screwdriver or skewer into hollow-sounding wood to inspect further. Be prepared to see skeleton-like wood and fat bugs crawling around.

If you’re squeamish about investigating wood boards or framing for yourself, call in your professional pest control company. The techs aren’t afraid to explore tight spots for frass and mud tubes.

You don’t have to get muddy and covered in spider webs to find out if you have termites. Pest control companies also properly identify termite species to provide the most effective treatments and control measures.

Contact Chem-Wise Ecological Pest Management today for termite control in the Chicago region, including the Aurora, Berwyn, and Rolling Meadows areas.