Q. How do termites find the wood they infest? Is it just random or can they key in on the wood in my house?
A. Actually, researchers don’t agree on how termites find their food sources. Some think that they mostly forage randomly, digging networks of tunnels until they find wood. Others believe they can track moisture, soil temperature, and other factors to find wood. Regardless, once they find wood, they have a system of recruiting other termites to the site and foraging becomes less random and more structured.
Termites prefer to feed on accessible wood in the ground rather than having to make mud tubes up foundation walls to reach wood in your home. When looking for wood above ground, termites build and travel through mud exploratory tubes so that they can travel between their underground colony and the food source (wood) without being exposed to drying air or predators like ants.
The foraging territory is centered around the termites’ nest and the size of that territory varies with the termite species, age of the colony, size of the colony, and availability of nearby food and other resources. Some large termite colonies can actually forage over an area the size of a football field, but most colonies don’t forage over their entire range at any one time.
Foraging termites leave pheromone trails, odors they secrete that other termites can follow. Once food has been found, other termite workers follow these pheromone trails from the colony to find and feed on the same food source. The strength of the pheromone trail depends on many things, including the size and quality of the food source.
The greater the number of foraging termites that find and feed on the new food, and that return to the colony, the stronger the trail becomes and the more new workers will follow the trail. It is a positive reinforcement loop. This is why termite baits are effective. Workers feed on the bait and bring it back to the colony where they feed it to others and also get workers to follow the trail back to the bait. But once the food is exhausted, the pheromone trail deteriorates and termites stop following it.