Fruit Flies These Fruit Flies are flightless or wingless fruit flies, so they are incapable of flying, unlike the fruit flies that you find in the wild. This is extremely helpful, but even though they can't fly, they are still incredibly fast little crawlers, so the best way to feed your mantis nymphs their fruit fly dinner is by stunning them into stillness right before feeding time. How do you do that? Well, you can actually put your entire fruit fly culture into the freezer for 2-3 minutes before feeding them out to your mantises. This is not long enough to kill them, but just long enough to give you a short window of a few minutes where they will not be able to move quickly. Immediately after removing the fruit fly culture from the freezer, tap an appropriate amount of fruit flies into your mantis enclosure, and then quickly replace the lid of the fruit fly culture. The fruit flies will then “wake up” safely inside the mantis enclosure, without any getting loose in your house!