Cluster Fly {Pollenia sp)

INSECT / TRUE FLY (DIPTERA) / BLOW FLIES(Calliphoridae)

These flies are parasites of the earthworm. They lay their eggs close to the burrows of earthworms and the larvae then infest the worms. The adults hibernate over winter, usually in houses and another name for them is Attic flies as they will seek refuge in areas they are unlikely to be disturbed.
It is very difficult to identify the individual species from photographs hence the binomial name ends in ‘sp’.
Further Information:Wikipedia

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