Flying insects that parasitise common starlings include the louse @-@ fly Omithomya nigricornis and the saprophagous fly Camus hemapterus . The latter species break off the feathers of its host and live on the fats produced by growing plumage . Larvae of the moth Hofmannophila pseudospretella are nest scavengers , which feed on animal material such as faeces or dead nestlings . Protozoan blood parasites of the genus Haemoproteus have been found in common starlings , but a better known pest is the brilliant scarlet nematode Syngamus trachea . This worm move from the lungs to the trachea and may cause its host to suffocate . In Britain , the rook and the common starling are the most infested wild birds . Other recorded internal parasites include the spiny @-@ headed worm Prosthorhynchus transverses .