What Do Hornets Eat? Prey, Nectar and Tree Sap by Season
What do hornets eat? Adult hornets hunt other insects for protein, then switch to nectar, tree sap and honeydew for their own energy. The two diets stay separate for a reason: adults cannot digest solid protein, so captured prey goes to the larvae, not into the adults’ own stomachs.
What Adult Hornets Eat
Adult hornets split their diet into two very different categories depending on who the food is for.
Prey They Hunt
Adult workers hunt beetles, large moths, dragonflies, mantises and cicadas, along with grasshoppers, flies and yellowjackets. European hornets (Vespa crabro) will even steal prey already wrapped in silk out of spider webs. They chew the catch into a soft paste before carrying it back to the nest, since they can’t digest the solid protein themselves.
Sugar They Eat Themselves
For their own nutrition, adults rely on sweet liquids: nectar from flowers, sap from tree wounds, juice from fallen fruit, and honeydew, the sugary excretion left behind by aphids and scale insects. European hornets are also known to chew bark off twigs and shrubs to reach the sap underneath, a habit that can girdle and kill young lilac stems.
What Larvae Eat
Larvae need protein to grow, and they get it exclusively from adult workers. A hornet returns to the nest with a chewed insect paste and feeds it directly to a larva, a food-exchange behavior called trophallaxis. In return, larvae secrete a fluid rich in amino acids and sugars that adults drink, so the exchange runs both directions. Prey choice depends on whatever is locally abundant: caterpillars, flies and other wasps are common picks.
Diet by Season
Hornet colonies change what they eat as the year progresses.
-
Spring: A lone fertilized queen hunts small prey herself to feed her first batch of larvae, since no workers exist yet to help.
-
Summer: Colony size peaks, and workers hunt heavily to keep up with larval demand while also visiting flowers for nectar.
-
Fall: Prey gets scarcer, so adults lean harder on fruit, sap and honeydew; this is also when hornets show up most often around picnics and trash cans.
-
Winter: Workers and the old queen die off after the first hard frost. Only newly mated queens survive, sheltering under bark or inside wall voids without feeding until spring.
Foraging and Food Sharing
Workers hunt individually rather than in coordinated swarms, returning to the same nest to unload prey or liquid food. Inside the colony, food moves between adults the same way it moves to larvae: mouth-to-mouth trophallaxis, which spreads both protein-derived nutrients and sugars to nestmates that stayed behind to guard the nest or tend the brood.
Why Hornet Diet Matters
Pest Suppression
Because hornets hunt caterpillars, flies and other soft-bodied insects in large numbers through summer, they function as a natural check on several garden and crop pests.
Incidental Pollination
Nectar visits are a side effect of their sugar habit, not a specialized behavior like a bee’s, but hornets still move pollen between blooms while feeding.
Conflicts With People
Fall’s protein shortage is the main reason hornets turn up around soda cans, fallen fruit and garbage in late summer and early fall. That shift in food source, not aggression, is usually what brings them into contact with people.
Living Near Hornets
A nest actively provisioning larvae will keep workers hunting nearby through summer; that activity drops off once the colony’s reproductive queens and males leave the nest in fall. Knowing the seasonal shift from hunting to scavenging explains most of the hornet encounters people report near homes.
