The only problem I had with fruit fly's is when they escape, lol. Also when you get wild fruit fly's in the house cuss of the medium used to culture them. Honestly, I rather use worms then fly's or crickets any day. You might want to look into them, they are more easy to care for and easy to feed, with less of a mess. You can try black worms or white worms. Yoou can usually find black worms at most fish stores and white worms on ebay.