Termites are small insects that live in colonies and feed on wood. Their favorite food is cellulose, which is the main component of plant cell walls. Termites have specialized digestive systems that allow them to break down cellulose and extract nutrients from wood. Understanding what termites like to eat is important for controlling them and preventing damage to wooden structures.
Wood-eating termites
There are different types of termites with different feeding habits, but the most destructive termites are the wood-eaters. Species like subterranean termites, dampwood termites, and drywood termites all consume wood as their primary food source. These termites construct tunnels and galleries in wood as they eat, weakening structures from the inside out.
Wood-eating termites prefer feeding on softer woods like pine that are higher in cellulose. Hardwoods like oak are more difficult for them to digest. However, given enough time, they will feed on any source of cellulose including wood products like paper, cardboard, and cotton. The cellulose in wood is a rich source of energy for termites.
Cellulose
Cellulose is a polysaccharide made up of long chains of glucose molecules. It is the most abundant organic polymer on Earth. Plants use cellulose to build strong cell walls. Wood is primarily made up of cellulose fibers bonded with lignin.
Termites produce cellulase enzymes in their gut that break the beta glycosidic bonds of cellulose. This frees glucose molecules that can then be absorbed and metabolized by the termite for energy. Cellulase allows termites to exploit wood as a food source.
Lignin
While termites can digest cellulose, they cannot breakdown lignin. Lignin is a complex polymer that helps strengthen and waterproof plant cell walls. Softwoods like pine contain less lignin than hardwoods, making them more palatable to termites. To access the cellulose, termites must tunnel through the lignin. Over time, extensive tunneling severely compromises the structure of wood.
Favorite wood sources
Given a choice, termites prefer feeding on certain wood sources over others:
- Pine – The high cellulose and low lignin content of pine makes it very attractive to termites looking for an easy meal.
- Fir – Another softwood with high cellulose content.
- Cedar – While cedar has natural repellent properties, termites will still feed on it readily.
- Spruce – A softwood that is rapidly consumed and hollowed out by termites.
- Aspen – A hardwood, but aspen contains less lignin than other hardwoods.
- Cottonwood – The soft wood of poplar trees is irresistible to termites.
These are all common landscaping and construction woods that offer termites an abundance of cellulose. In contrast, termites avoid feeding on wood sources like:
- Teak – Very dense hardwood with natural insect repellent oils.
- Redwood – High levels of tannin make it less appetizing.
- Chestnut – Dense hardwood is difficult for termites to digest.
- Black locust – Hardwood with high resistance to rot and insects.
These woods deter termites with their density, compounds, and resistance to decay. However, no wood is completely immune to termite damage when they are persistent.
Favorite wood products
In addition to natural wood sources, termites also feed on wood products containing cellulose:
- Paper
- Cardboard
- Particle board
- Plywood
- Furniture
- Drywall
- Books
- Cotton
- Basket materials
Paper products are like candy for termites. These materials are rarely treated to resist insects and provide a great source of unmodified cellulose. Furniture, books, and construction materials containing wood fibers or cellulose fillers are also prime targets.
Favorite wood locations
Termites need moisture to thrive. They favor wood sources in these damp locations:
- Basements
- Crawl spaces
- Untreated mulch near foundations
- Wood contacting soil
- Leaky plumbing
- Poor drainage areas
- Wood debris under patio stones
- Tree roots
- Hollow logs
Subterranean termites tunnel up from the soil to feed on damp basement and crawlspace beams. Outdoor mulch provides moisture and a bridge to the home’s wood framing. Leaks wet the wood and attract termites. Eliminating moisture is key to starving them out.
What don’t termites eat?
While termites feed primarily on wood and wood products, there are some other cellulose materials they avoid:
- Concrete – No cellulose.
- Plastic – Synthetic polymers, not cellulose.
- Steel – Inorganic metal.
- Glass – Inorganic silica.
- Stone – Inorganic minerals.
Using inorganic building materials like concrete foundations and steel support beams helps prevent termite damage. Plastics can also deter termites. However, plastic foam insulation may contain cellulose fillers that attract them.
Non-cellulose foods
While cellulose provides the bulk of their diet, termites will also consume non-cellulose materials at times for moisture and nutrients:
- Dirt particles
- Fungi
- Lichens
- Algae
- Waste paper coatings
- Adhesives
- Wallpaper
- Drywall coatings
Termites scrape these trace materials while tunneling through wood. Small amounts of fungal hyphae, algae, lichens, and adhesives help supplement their diet. However, they cannot survive without cellulose as their main food source.
Conclusion
Termites evolved to feed on cellulose, allowing them to unlock the energy stored in plant cell walls. Their favorite foods are wood sources high in cellulose like pine, fir, and cedar. Damp woods attract termites. While no wood is completely resistant, some woods like redwood and teak are less vulnerable. Paper products made from cellulose offer an irresistible food source for termites. Eliminating moisture and using inorganic materials can help deter termite damage, but they will feed on any available cellulose in time.
