Carpenter ants absolutely eat sugar. In fact, sugar is the single most important fuel source for adult worker ants, providing the energy they need to forage, excavate wood, and maintain the colony. This catches many people off guard because carpenter ants are so closely associated with wood damage, but they don’t actually eat the wood they tunnel through.
Why Sugar Matters More Than Wood
One of the most common misunderstandings about carpenter ants is that they eat wood the way termites do. They don’t. Carpenter ants lack the digestive enzymes needed to break down cellulose, the tough fiber that makes up wood. They excavate it purely to create nesting galleries, pushing the sawdust-like debris (called frass) out of the nest. Their actual nutrition comes from foraging.
Carbohydrates, especially simple sugars like fructose and glucose, are the primary energy source for adult workers. These sugars cross the gut wall quickly and get metabolized right away. Research on ant colony longevity has consistently shown that colonies fed a high-carbohydrate, low-protein diet live longer than those given the reverse, which tells us ants prioritize sustained sugar intake above almost everything else. Protein matters too, but mainly for queens producing eggs and larvae that need to grow. The workers running the colony day to day are fueled by sugar.
Where Carpenter Ants Find Sugar in Nature
In the wild, carpenter ants get most of their sugar from honeydew, a sticky, sweet liquid produced by aphids, scale insects, and other sap-feeding bugs. These insects feed on plant juices and excrete excess sugar, which ants eagerly collect. Studies on western carpenter ants found that workers specifically seek out honeydew for its sugar content rather than for any other nutrients it might contain. This relationship is so valuable that ants will actively tend and protect aphid colonies, essentially farming them for a steady sugar supply.
Beyond honeydew, carpenter ants also feed on ripe fruit, tree sap from wounds in bark, flower nectar, and the juices of dead insects. Their diet is genuinely varied, including both plant and animal materials, but sugar-rich sources are the consistent thread.
Sugary Foods That Attract Them Indoors
Inside your home, carpenter ants are drawn to the same sweetness they seek outdoors. They’ll feed on syrup, honey, granulated sugar, jelly, candy, fruit, and sodas. They’re also attracted to meats, pet food, and fats, but sugary items tend to be the strongest draw.
Early spring is when you’re most likely to notice this. If a colony has established itself inside a wall or other structural wood, workers start foraging before outdoor food sources become available. They’ll show up in kitchens and bathrooms, looking for both water and sweet foods. A trail of ants heading toward a sugar bowl or a sticky spot on the counter is a classic early sign of an indoor carpenter ant colony.
How Sugar Gets Shared Across the Colony
When a foraging worker finds a sugar source, she doesn’t just eat her fill. She stores the liquid in a specialized pre-digestion organ called the crop, sometimes referred to as a “social stomach.” Back at the nest, she regurgitates this stored food and passes it mouth-to-mouth to other ants in a process called trophallaxis. Only a small fraction of workers actually leave the nest to collect food. The rest of the colony, including the queen, nurses, and larvae, depend entirely on this sharing network to eat.
This is why sugar-based baits can be so effective against carpenter ants. A forager picks up the bait, brings it back, and distributes it throughout the colony. The sugar acts as the delivery vehicle. You can exploit their sugar preference by setting out a simple mix of equal parts sugar and milk near ant trails, then following the workers back toward their nest to locate it.
Sugar Preferences Are Specific
Not all sugars are equally attractive to carpenter ants. Research published in Royal Society Open Science tested western carpenter ants on a range of sugars and found they show clear preferences among different types. Simple sugars like fructose and glucose, the same sugars found in fruit and honey, are rapidly absorbed and preferred. This selectivity means that the type of sweet food available can influence how strongly ants are attracted to a particular spot in your home. Honey, fruit juice, and soda (which contain fructose and glucose) tend to be more reliably attractive than foods sweetened only with more complex sugars.
Reducing outdoor honeydew sources can also help. Because carpenter ants are so dependent on aphid honeydew, controlling aphid populations on plants near your home’s foundation can make the area less appealing to foraging ants in the first place.