I was wondering if I could create humidity in my enclosure by filling a jar with water and poking some small holes in the lid. I know many ppl just use damp coir. The reason I do not want to do this if I can avoid it is because I have a millipede cage that I keep moist and it is a source of concern every summer. I get a crap-ton of small black flies with their wormlike maggots and grain mites and swarms of fruit flies (I swear I inhale thousands ). So I don't want another cage where these nuisances can spread.
Also, if this idea is viable, will the roaches still breed with ambient humidity