Those look like parasitic wasps. With some species, you can get dozens out of a single host so when they emerge as adults, it seems like a small swarm.

It's possible that this is a one-time thing--that whatever they came out of isn't coming back. (If you keep having them, well, never mind that theory!!)

If you can get a better picture we might be able to tell what they are and what they have been parasitizing. That will help you discourage them. In the meantime, it's unlikely that they are hurting your worms and they are usually beneficial.

Thanks for you reply Fori!

Here are some better pics. There are certainly many of them. They only appear late morning and go away late afternoon. When i dig through the farm i can't see them amongst the worms so I'm really not sure where they go in between times. Otherwise they all fly around the farm area.

Much better! Not that I know what they are...definitely parasitoid wasps though. Do you have tomatoes nearby, or some other source of nice fat caterpillars (or pupae)?

Hopefully someone with parasitoid ID skills will see this. They have some distinctive features that ought to be helpful.

I can't imagine them doing anything harmful though (unless maybe you're raising butterflies). I think it's just coincidence that they are near your worms. But an ID would certainly clear that up.

I don't really grow many veggies.. i have a citrus tree that doesn't bear fruit.. hard to know where they would be coming from.

It's good to know they wont harm my worms. I wouldn't mind them expect that they are making a good portion of my balcony pretty unpleasant!

Thanks for your help!

Do the wasp harm worms?

No they don’t seem to harm the worms that I can tell.

To get rid of pests like these, add new bedding, don't feed for two weeks and they usually go away.