Flash freezing the fruit flies by dumping them into a frozen cup is my preferred way of feeding the flies to my ants. They don't seem to mind the cold flies, so I would imagine freezing them would be just fine, I just wouldn't plan on keeping them to long as the freezer may dry them out to the point where they won't be desirable to the ants.
Edited by CallMeCraven, March 13 2018 - 7:31 AM.
6x Crematogaster spp. Three with eggs, three without
1x Formica argentea
Harmony with land is like harmony with a friend; you cannot cherish his right hand and chop off his left.