The thornbill and the ant

I was watching a striated thornbill the other day when it had this interaction with an ant. The thornbill is insectivorous, and the ant is much smaller - and a reasonable-sized morsel. The ant and the bird were suddenly face to face. But the bird didn't eat the ant: it backed off, waited until the ant had finished, and only then moved in. Ants farm aphids, and thornbills love aphids, so leaving the ant do do its thing makes much more sense than eating it. But it suggests the thornbill has a much more sophisticated view of the world than that with which we normally credit any animal - except ourselves.