If you need to store your Fly Predators before releasing them, simply keep them in their pouch which is sealed, but breathable. They will keep this way for 3 days after they start emerging without any adverse effects. If absolutly necessary to hold for a longer period of time put the pouch containing the Fly Predators in the refrigerator as soon as it arrives. Their productivity slowly decreases if kept longer than about 5-7 days.