Flies in my worm farm, is my worm farm ok?

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Question by *-*-*-*-*-*-*-*: Flies in my worm farm, is my worm farm ok?
I have a worm farm, currently using two trays. I opened it today to feed the worms and several large black flies flew out of it. The fluid that flows from the tap is almost black with tiny white floating things (possibly eggs/larvae or insects. The fluid also smells like sewerage but the contents of the trays do not smell. This doesn’t sound right or is it?

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