The majority of insects have two pairs of wings. Flies possess only one set of lift-generating wings and one set of halteres. The order name for flies, "Diptera", literally means "two wings", but there is another order of insect which has evolved flight with only two wings: strepsipterans, or stylops; they are the only other organisms that possess two wings and two halteres. The strepsipterans have adapted their forewings into halteres, whereas dipterans have adapted their hindwings into halteres. This unique structure which detects rotations/perturbations during flight has never been described in nature elsewhere, though many flying insects have been shown to detect Coriolis forces from their non-specialised wings.