Fruit Flies

Despite it being January, and despite having no actual fruit out to speak of, my fiance's house is inundated with fruit flies. We're thinking they come into the house as an added little "gift" with the crickets we buy to feed the lizards (the same companies that breed feeder crickets sometimes breed fruit flies as a starter food for babies of small lizard breeds), but they sure seem to be thriving in the household. So far we've put out sticky tape, which has a moderate margin of success, and a mason jar with juice in the bottom and a funnel in the top so that they can fly in but not out. It just started this morning, but hasn't caught sweet bugger all yet.

So, here's my question: any tips for getting rid of the little pests? Anybody else have problems with them? Thinking of sprinkling diatomaceous earth into the cricket bins, but somehow I feel this might kill the crickets as well?