Mostly insects. Trap-jaw Ants are predators, and in the wild they hunt small, soft-bodied insects like termites with their snapping mandibles. They also feed on aphid honeydew and extrafloral nectar.
In captivity, offer pre-killed insects 2 to 4 times a week and clear the leftovers within a day. Fruit flies, cockroach nymphs and sliced mealworms all work, and termites are a favorite. They need more protein than most ants; without enough of it, they'll eat their own brood.
For carbohydrates, give them droplets of sugar water or a slice of organic apple dusted with sugar, since they rarely drink from feeders. Once a week, offer our Honeydew Honey in a feeding dish. It's closer to what they feed on in the wild.
Our care guide has more information on what they eat.