Termites, carpenter ants, and other wood-boring insects can cause considerable damage to a wooden structure if not noticed or neglected. The damage in the USA is about $5 billion per year, and most often it is not covered by insurance. Wood-boring insects can get into a structure through cracks or voids in the foundation wall, or under stucco walls. One needs to be on guard for visual damage by inspecting sills, floor joists, sub-floors and cracks in concrete foundations. Also look around windows, under porches, and any location where wooden surfaces join up with concrete foundations.
Subterranean Termites usually work at night when more moisture is available. They create tunnels or tubes up walls from under-ground nests of about ¼ inch to 1” diameter made mostly of mud, up to a height of 6 feet or more. They can create tunnels on concrete or stone as well as wood. They will make tunnels under-ground in their nest to create different rooms for the termites as the colony grows. The termites will also tunnel under the wood surface as they eat the cellulose with the tunnels running along with the wood grain. This leaves a thin veneer of wood on the surface.
Only the worker termites do the tunneling, with the king and queen termites doing the reproduction. The workers are about ¼ inch long and white in color. The kings and queens are about ½ inch long and black or brown in color.
Methods of Controlling Termites include a borate infusion treatment into the wood at the factory, or using a poison to treat the surrounding ground and entry points, or applying a termite-avoiding coating to the exterior and interior surfaces that are susceptible to attack. The borate wood treatment is only as effective as the porosity of the wood being treated. The borate is water-soluble, so it can be leached out in time in wet environments, or where exposed to rain. It is not to be used under-ground.
Commonly used poisons that are spray-applied are hazardous to use with an acute toxicity for inhalation or oral exposure, and have a hazard rating of 4. One needs to have full body protection when spraying, and others need to be out of the vicinity. These poison sprays are not recommended for interior applications. They can cause headaches, nausea, convulsions, flu-like symptoms and seizures. They need to be sprayed again every year to maintain protection.
The best long-term solution is to use a termite inhibiting coating on all potential affected surfaces. There is a coating that termites will not eat through, and they will avoid building tunnels on it. It is a water-based coating that is non-hazardous to apply and use, water-resistant, and lasts for years like a normal paint. If the building is currently infested, the colony will have to be exterminated before application to prevent further damage.