 Many species of birds — mostly cuckoos, woodcreepers, tanagers, and antbirds — feed near the swarms.About 50 of the approximately 200 species of antbirds specialize in preying on insects fleeing the ants, getting up to half their food this way.Some of these birds actively check army-ant bivouacs each morning and follow the foraging trail to the swarm front, where they take positions based on their species' relations in a dominance hierarchy.