Thick Headed fly

Although this species is classed as 'common', i.e. widely distributed throughout the UK, I have only ever seen it on the one occasion. It is certainly a distinctive species and with its widely spaced prominent eyes separated by yellow facial hair, it lives up to its common name of a 'Thick Headed fly'.
It is a parasite of bumble bees, actually laying a solitary egg on the bee. Considering how busy and active bumble bees can be when foraging for pollen, this is no mean feat. On hatching, the larva matures inside the bee.