Ants eat a surprisingly wide range of foods, but nearly every species relies on two nutritional pillars: sugars for energy and protein for growth. What varies is how they get those nutrients. Some species farm fungus, others harvest seeds, and most common backyard ants survive on a combination of sweet liquids and dead insects. If you’re keeping a pet colony or just trying to understand what draws ants into your kitchen, the specifics matter.
Sugar: The Fuel That Drives a Colony
Sugar is the primary energy source for adult worker ants, and their relationship with it stretches back millions of years. As flowering plants evolved, they began secreting sugary liquid from bark and blossoms, essentially paying ants to patrol their branches and kill leaf-eating caterpillars. That evolutionary bargain still plays out today: tropical species climb into the forest canopy daily to drink sugar water that seeps from plants.
The other major sugar source is honeydew, a sticky liquid produced by aphids and other sap-sucking insects. Many ant species actively “farm” aphids the way humans keep cattle, protecting them from predators and moving them to fresh plants in exchange for a steady supply of honeydew. This liquid contains multiple sugars, including fructose, glucose, sucrose, and several more complex sugars, along with small amounts of amino acids like glutamic acid and asparagine. It’s a nearly complete snack: quick energy plus a trace of protein.
In homes, this sugar drive is why ants swarm toward soda cans, syrup spills, and ripe fruit. Even unrinsed drink containers or a thin film of jam on a countertop can recruit a foraging trail within hours.
Protein: What the Brood Needs to Grow
While adult workers run on sugar, the colony’s larvae, queen, and developing brood depend heavily on protein. Queens fed a protein-rich diet produce significantly more eggs, and colonies with ample protein raise more reproductive ants. Without enough protein, a colony stagnates.
Most ant species get protein by scavenging dead insects or actively hunting small invertebrates. A worker that stumbles across a caterpillar, beetle, or fly will recruit nestmates to carry it back. Inside the nest, workers chew the prey into smaller pieces, but here’s where things get interesting: adult ants can barely eat solid food themselves. Their mouths contain a filter of tiny hairs that blocks particles larger than about 1 to 150 micrometers, depending on the species. Essentially, adult ants are limited to liquids and extremely fine particles.
This is where larvae become critical. Workers pass solid protein to the larvae, which can chew and digest it normally. The larvae then process the food and share some of the nutrients back to the adults as a liquid secretion. Biologists refer to larvae as a “digestive caste” because the colony literally depends on its young to unlock the nutrition in solid food. It’s a two-way relationship: adults feed the larvae, and the larvae feed the adults back.
How Ants Actually Eat
Adult ants take in food two ways. For liquids, they extend a tongue-like structure covered in fine hairs that picks up fluid through adhesion, then retract it to pull the liquid into a pumping chamber in the head. Some species lick rhythmically, others hold their mouthparts still and passively suck. For solids, the mandibles (the large pincers) break food into tiny fragments outside the mouth before any of it enters the digestive system.
Once a forager collects liquid food, she stores it in a special “social stomach,” a crop separate from her own digestive tract. Back at the nest, she regurgitates droplets mouth-to-mouth to other workers, the queen, and larvae. This sharing system, called trophallaxis, means a single forager can feed dozens of nestmates from one trip. It also means that when you see a line of ants heading toward a sugar source, only the foragers are eating directly. The rest of the colony eats secondhand.
Specialists: Fungus Farmers and Seed Harvesters
Not all ants are generalists. Leafcutter ants, found across Central and South America, don’t eat the leaf fragments they famously carry home. Instead, they feed the leaves to a specific fungus they cultivate in underground gardens. The fungus breaks down tough plant fibers that the ants can’t digest on their own, and the ants then eat the fungus. It’s their only food source. If the fungus dies, the colony dies with it.
This farming system has been running for roughly 50 million years. When a new queen leaves her birth colony to start her own, she carries a small piece of the fungus in her mouth. She tends the garden alone for about a month, waiting for her first workers to mature before they take over foraging and farming duties. Larger workers cut and transport leaves while smaller workers care for the fungal gardens and brood.
Harvester ants take a different specialized approach, collecting seeds as their primary food. They crack seeds open with their powerful mandibles and store them in dry underground chambers. Some species even remove the outer husks and arrange seeds to prevent mold growth, creating something like a primitive granary.
What Attracts Ants Indoors
The foods that draw ants into your home mirror their natural diet. Sweets and sugary residues are the biggest attractant, but grease, cooking oil, pet food, and protein-rich scraps also pull them in. Oregon State University’s pest management program identifies five main attractants in homes: sweets, sugar, pet food, grease, and protein.
Storing attractive foods in sealed containers with tight-fitting lids is the most effective deterrent. Rinsing cans and food packaging before recycling removes the residue trails that foragers follow. If you have aphid-infested houseplants, the honeydew those aphids produce can attract ants indoors even when your kitchen is spotless.
Feeding a Pet Ant Colony
If you’re keeping ants, the goal is replicating their natural nutritional balance. A good baseline is offering protein at least twice a week and a sugar source at least once a week.
- Protein sources: Feeder insects work best. Mealworms, superworms, crickets, and fruit flies are all reliable options. In a pinch, small pieces of cooked chicken, beef, ham, or egg (plain, with no seasoning or condiments) will work.
- Sugar sources: Mix one part table sugar with four parts water to make a simple sugar water. You can offer it on a small cotton ball or in a shallow dish to prevent drowning. Honey diluted in water is another option, though raw honey carries a slight mold risk in humid formicariums.
- Specialist diets: Harvester ants need seeds as their staple food. Chia, flax, and grass seeds are common choices. Leafcutter species need fresh plant material to feed their fungus, which makes them significantly more complex to keep.
Protein becomes especially important when your colony has a laying queen and growing brood. Colonies with more available protein produce more eggs and raise larvae faster. If you notice brood production slowing, increasing protein feedings is usually the first adjustment to make. Remove uneaten food within 24 to 48 hours to prevent mold, which can devastate a colony in an enclosed nest.