You hear it all the time: termites eat wood. It’s the classic answer, the one-line horror story for any homeowner. But if you stop there, you’re missing the whole plot. Asking "what is a termite's favorite food?" is like asking what a teenager's favorite food is—pizza might be the easy answer, but it doesn't explain the metabolism, the cravings, or the havoc they can wreak on your kitchen. The real story is about cellulose, and understanding that distinction is what separates a worried homeowner from an informed one.

I’ve seen the aftermath for years. The floor that feels spongy, the beam that’s hollowed out like a chocolate Easter bunny, the frantic call after a winged swarm appears in the living room. The common thread in every single case wasn't just "wood." It was a specific, digestible component of wood that termites are evolutionarily obsessed with finding.

The Cellulose Obsession: It’s Not Just Wood

Let’s get technical for a second, but I’ll keep it simple. Wood is made of three main things: cellulose, hemicellulose, and lignin. Think of it like a concrete wall. Cellulose and hemicellulose are the strong, flexible rebar. Lignin is the hard, cement-like binder holding it all together.

Termites don’t want the concrete. They want the rebar—specifically, the cellulose. It’s a complex carbohydrate that’s incredibly tough for most animals to break down. Cows need a four-chambered stomach. We humans can’t digest it at all (that’s why celery is "roughage").

So how do these tiny insects manage it? They cheat. They employ a gut full of microscopic protozoa and bacteria (in the case of subterranean termites) or specialized bacteria alone (in drywood termites) that produce enzymes to break cellulose into simple sugars. The termite feeds its gut microbes, and the microbes feed the termite. It’s a perfect, hungry partnership.

Termite Types & Their Specialized Menus

Not all termites have the same dining preferences or table manners. Where they eat is as important as what they eat.

See the pattern? Moisture is the universal appetizer. For subterranean and dampwood termites, it’s a strict requirement. For drywood termites, they still get most of their water from metabolizing the wood itself, but they’ll seek out wood that isn’t completely desiccated.

I once inspected a home where the drywood termites had targeted a single, north-facing window frame that caught occasional condensation. The rest of the house was fine. They found their micro-climate buffet.

Beyond the Wood Pile: Surprising Items on the Menu

This is where the "cellulose" fact gets real for homeowners. If you think your concrete slab foundation or vinyl siding makes you safe, think again. Termites are explorers, and their hunger drives them through anything to get to cellulose.

Here’s a list of non-wood items I’ve personally seen damaged because they contained cellulose or provided a path to it:

• Drywall Paper Backing: The paper on both sides of drywall sheets is pure cellulose candy. Termites will eagerly consume it, leaving a thin veneer of paint or gypsum that crumbles at a touch.
• Cardboard Boxes: Storing cardboard boxes in a damp basement or crawl space is like laying out a welcome mat. It’s an easy, initial food source that can support a colony while they scout for structural wood.
• Books, Paper, and Insulation: Certain types of insulation, like cellulose insulation (blown-in recycled newspaper), are literally a termite feast. Old books in a garage are also at risk.
• Plant-based Fabrics: In severe infestations with no other food, I’ve found damage to cotton-based materials, like the backing of old carpets.

What About Treated Wood?

Pressure-treated lumber is infused with chemicals (like ACQ or copper compounds) that are toxic to termites. It’s resistant, not immune. In a lab, they’ll avoid it. In the real world, if it’s the only wood connecting a colony to soil, or if it’s old and the treatment has leached out, they may test it or tunnel through it to get to untreated wood. Never assume treated wood is a complete barrier.

The Home Invasion Blueprint: From Food to Damage

Understanding their favorite food explains their hunting strategy. Subterranean termites operate like a mining company. Worker termites (the blind, hungry ones) fan out from the colony through underground tunnels or above-ground mud tubes. They are constantly tapping and tasting with their antennae and mouthparts, seeking the chemical signature of cellulose and moisture.

When they find it—say, a damp wooden joist in your crawl space—they release pheromones to create a scent trail. Hundreds more workers follow the trail. They don’t eat the surface. They start hollowing it out from the inside, following the softest grain (the springwood, richest in cellulose), leaving a thin exterior shell and a labyrinth of galleries packed with mud and feces.

This is why damage is often catastrophic before it’s visible. The wood can look normal on the outside but be completely gutted inside. A common test is to poke a screwdriver into a suspect beam. If it sinks in easily with little resistance, you’ve likely found their dining room.

Protecting Your Home’s "Buffet"

Knowing their goal is cellulose and moisture lets you build a defense. It’s about making your home’s cellulose inaccessible and undesirable.

1. Eliminate the Moisture Appetizer

• Fix leaky faucets, pipes, and AC units immediately.
>Ensure gutters and downspouts direct water at least 5 feet away from your foundation. >Use a dehumidifier in damp basements and crawl spaces. Keep these areas well-ventilated. >Grade soil so it slopes away from your house.

2. Remove the Food-to-Soil Connection

• Store firewood, lumber, and cardboard boxes off the ground and away from your home’s exterior walls.
>Maintain an 18-inch gap between any soil or mulch and your home’s wooden siding or trim. >Use concrete, stone, or metal barriers where wood posts meet the ground.

3. Deny Easy Access

• Seal all cracks and crevices in your foundation, even tiny ones.
>Ensure window and door screens are intact. >During construction or renovation, consider installing physical termite barriers (like stainless steel mesh) or using pre-treated materials in critical areas.

4. The Professional Safety Net: Regular Inspections

Even with perfect prevention, an inspection by a licensed pest control professional once a year is non-negotiable. They look for the subtle signs you might miss: mud tubes, discarded wings, frass, and tell-tale tapping sounds in wood. According to research from entities like the USDA Forest Service, early detection is the single biggest factor in reducing repair costs.

Your Top Termite Diet Questions, Answered

Let’s tackle the specific, gritty questions that keep popping up. These go beyond the basic "what do they eat."

Do termites ever run out of food and die off?

In a natural forest, yes. A colony will consume a fallen log and then either die or migrate. In a human home, it’s a different story. Your house represents a massive, concentrated, and often interconnected food source. A large, established subterranean colony can forage over an area the size of a football field. They can shift from an exhausted floor joist to a nearby wall stud without the colony ever feeling a pinch. In a home, they rarely "run out." They just keep eating until they’re stopped.

Can I use "termite-resistant" woods like cedar to prevent them?

This is a classic half-truth. The heartwood of cedars, redwoods, and some tropical hardwoods contains natural oils and resins that termites find distasteful. It’s a decent deterrent for things like fence posts or exterior trim. But the sapwood (the outer layer) of these same trees is not resistant. More importantly, termites are not deterred by taste if they’re hungry enough or if the wood is the only bridge to moisture. I’ve seen cedar siding riddled with termite tunnels where it touched wet soil. Never rely solely on wood choice as your defense.

Why do I sometimes see termites swarming inside my house? Are they eating something new?

The swarmers (alates) are the reproductive termites. They don’t eat wood at all. Their sole purpose is to fly out, pair up, and start new colonies. If you see a swarm inside, it means there is already an established, mature colony inside your home’s structure that has produced these winged offspring. It’s a major red flag, not a sign of a new foraging party. The workers are already there, eating away, out of sight.

So, what is a termite's favorite food? It’s cellulose, served with a side of moisture. Wood is just the most common delivery vehicle. By shifting your thinking from "wood" to "cellulose sources," you start seeing your home through a termite’s senses. You see the stacked firewood, the damp cardboard in the basement, the soil piled against the siding. That awareness is your first and most powerful line of defense. It turns a vague fear into a specific, actionable plan to protect what’s yours.