Little black flies in my vinegaroon enclosures????

[Balkastalkman]

I am keeping 3 adult vinegaroons in a 20 gallon with dividers. Lately i noticed a substantial amount of these flies all over the place in there. They are smaller than fruit flies and have black bodies. I check on my vinnies and they are fine but i do wonder what these flies are. Im going to change their substrate asap but if the flies are harmless i dont see a point. I know a few of you guy have seen this. So give me your input, what are they and what do i do?

 

[ZephAmp]

I am keeping 3 adult vinegaroons in a 20 gallon with dividers. Lately i noticed a substantial amount of these flies all over the place in there. They are smaller than fruit flies and have black bodies. I check on my vinnies and they are fine but i do wonder what these flies are. Im going to change their substrate asap but if the flies are harmless i dont see a point. I know a few of you guy have seen this. So give me your input, what are they and what do i do?

Fungus gnats. They breed in moist coconut fiber with even the slightest amount of extra organic matter. Generally you'll see an initial boom when you put in new substrate but they will eventually go away.

 

[Balkastalkman]

are they at all harmful, should i even bother changing the substrate ?

 

[ZephAmp]

are they at all harmful, should i even bother changing the substrate ?

The larvae (maggots) eat organic matter in the coconut fiber. I believe the adults do not feed or feed very little on fungi, plant matter, nectar, etc. They will not harm your inverts.