Small red worms in rainwater barrel

The best way to propagate them is what you are already doing: provide a place for them to breed. The midges would be difficult to cultivate indoors; the flying adults need room to form mating swarms.
 
:iagree:

the blood worm you see is probably the pupal stage of their life cycle.

the adult is a fly (looks like a tiny mosquito)

btw..they are wonderful food for Oncorhynchus mykiss Rainbow trout..as well as other salmonids.
 
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