Well I have stumbled across one of the few pitfalls in keeping an indoor worm bin. Seeing as I go on about the benefits of keeping a vermicompost bin, I thought I should likely pass on a warning as well.
The organic waste that feeds composting worms so well, can also attract pests like gnats and fruit flies. In my case, I had gotten a bit lax with some non-bin garbage in the kitchen. This led to a minor fruit fly infestation. Now, I know how to build a fruit fly trap, and did so. But some of the flies made it into one worm bin, in which I had placed some old grapes that I neglected to properly cover in bedding for just one day. Since fruit flies propagate so quickly, the next time I opened the box I was greeted by a host of exiting flies. I immediately added cardboard and chopped straw but it was too late. Evidently many eggs were already laid and juvenile fruit flies have been crawling out from the straw like so many zombies erupting from fresh graves.
I have added another trap right inside the worm bin, and have placed some dark plastic over the lid. This should keep the young flies from being drawn to the light through the ventilation holes. All I can really do now is leave the bin this way until all the decomposing vegetable matter has been processed and the feeding/breeding cycle of the flies has been interrupted. We'll see how that goes.
As far as avoiding this situation in the future, the key is ensuring that added food is always covered in bedding. This is a good idea anyway, since it also cuts down on odors and provides a better Carbon to Nitrogen ration. But it DOES make it harder to watch the worms cluster to feed, which is a priority for many...especially before the novelty of keeping worms wears off.
Hopefully this warning doesn't turn people away from vermiculture.
Peace and comfort.
22 hours ago