I've been researching more natural solutions, and I was coming up empty until this thread started. I just own one chameleon (no other pets at all), so keeping another pet, a gecko, isn't really a fitting solution for some fruit flies especially since they're all around the room and not just the enclosure. I really like the sand idea as well for the op's problem as well. I'm still trying to figure out the source of my fruit flies since it only became a problem as the weather started cooling off, and in my situation I don't think it's coming from my plants. Just curious if anyone had experience with the ultrasonic pest repellers as I keep troubleshooting my own situation.Use something more natural.
House geckos, or day geckos. Small species like that will chase the flies.If you cage is suitable for a chameleon, it will keep these small geckos alive too.
I like the sand idea too. It won't hurt the plants as long as there is soil under it