Once a female scale insect has plumbed herself into her food plant of choice and started sucking the sap that flows forth, she has no reason to go anywhere ever again.
A life of total immobility requires no functional wings, or even legs, but defences are essential, so these close relatives of aphids secrete a resinous shield for protection.
The resin of some species is the source of shellac, once used to make gramophone records and still a component of wood varnish and nail polish.
