Yes i know a lot of people do that feed dry in the summer and i understand why because the flies can be a pain in the arse,i just put a portion i think they will be able to eat and i feed it at night when it gets cooler.I just check in the morning if theres any remains left and clear it out. ATB
i keep my ferrets near to one of my kitchen windows. the mrs gets on my back a bit it if theres any flies about. even if i did as you suggested there would still be the smell of meat to attract them......................... plus i'm bit to lazy to clean out the ferrets every day too