Subterranean termites are destructive pests that can cause significant damage to homes. Understanding their appearance and the signs they leave behind is important for early identification. This article describes subterranean termites and their presence, helping you distinguish them from other insects and recognize their activity.
Physical Characteristics of Subterranean Termites
Subterranean termite colonies consist of different castes. Workers are the most numerous, appearing small (1/8 to 3/8 inches long), cream-colored, and soft-bodied. These wingless termites forage for food, build tunnels, and care for the colony.
Soldier termites are wingless with creamy bodies, identifiable by their larger, brownish heads and prominent mandibles (pincers) used for defending the colony. Reproductives, also known as alates or swarmers, establish new colonies. They are larger than workers and soldiers (1/4 to 1/2 inch), ranging from dark brown to black. Swarmers possess two pairs of long, translucent wings of equal size, which they often shed after their mating flight.
How Subterranean Termites Differ from Ants
Subterranean termites are frequently confused with ants, especially during swarming events when both may have wings. However, several key physical differences can help distinguish them. Termites have straight, bead-like antennae, while ants have distinctly elbowed antennae that bend at a 90-degree angle.
Another distinguishing feature is their waist. Termites have a broad, thick waist, giving their body a uniform shape. Ants, however, possess a constricted, narrow waist, creating three distinct body segments. For winged individuals, termites have two pairs of wings that are roughly equal in size and length. Winged ants have forewings noticeably larger than their hindwings. Termite wings are often shed easily after swarming, unlike ant wings.
Common Signs of Subterranean Termite Presence
While seeing the termites themselves can confirm an infestation, several other visual cues indicate their presence. Mud tubes are a primary sign, appearing as pencil-width, earthy-brown tunnels constructed by workers from soil, wood particles, and saliva. These tubes, commonly found on foundations, walls, or wooden structures, protect termites from dry air and predators as they travel between their underground nests and food sources.
Damaged wood caused by subterranean termites often looks hollowed out, with tunnels or galleries that follow the wood grain. Termites consume the softer springwood, leaving behind the harder summerwood, which can make the wood appear layered or splintered. The surface of infested wood may appear intact, but it can crumble easily or sound hollow when tapped.
Another strong indicator of a termite infestation is the presence of discarded wings. After reproductive termites complete their swarming flight, they shed their wings, often leaving piles of these small, translucent wings near windowsills, light fixtures, or other entry points. Unlike drywood termites, subterranean termites do not produce visible, pellet-like frass (droppings); instead, their excrement is used in the construction of mud tubes.