Vicia faba
"Lasius niger" removes predators such as ladybirds from the vicinity of black bean aphid thus keeping their "milch cows" safe. On a test plot of field beans ("Vicia faba"), plants without black bean aphids yielded an average of 56 seeds per plant, those with aphids and no ants yielded 17 seeds, and those with both ants and aphids averaged eight seeds per plant. "Vicia faba" also produces extrafloral nectaries that "Lasius niger" can feed from directly.