Controlling fruit flies

[Shuos Zehun 0]

Is there anything I can add to my enclosure to help control fruit flies?  Does anything eat them that won't eat roaches?  I try to give my hissers lots of fresh fruit (they LOVE oranges)  and it attracts fruit flies more or less instantly.  I have a fruit fly trap in the cage (tub of grape juice and soap with holes in the top) but it doesn't catch nearly enough.  I realize the flies probably aren't bothering the roaches, but they're bothering *me* 😉