In antiquity, yarrow was known as herbal militaris, for its use in stanching the flow of blood from wounds. In classical Greece, Homer tells of the centaur Chiron, who conveyed herbal secrets to his human pupils and taught Achilles to use yarrow on the battle grounds of Troy. Other common names for this plant include: bad man's plaything, bloodwort, carpenter's weed, death flower, devil's nettle, eerie, field hops, hundred leaved grass, knight's milefoil, knyghten, nosebleed, old man's mustard, old man's pepper, sanguinary, seven year's love, snake's grass, soldier's woundwort, stanchweed, thousand seal, and woundwort. Several cavity-nesting birds, including the common starling, use yarrow to line their nests. Adding yarrow to nests may inhibit the growth of parasites. Yarrow has been used medicinally throughout history. In the Middle Ages, yarrow was part of a herbal mixture known as gruit used in the flavoring of beer prior to the use of hops. Traditional medicine herbalists have used common yarrow for its astringent and analgesic effects. And in the Hebrides a leaf held against the eyes was believed to give second sight!