Natural Fly Spray 1 quart Raw Apple Cider Vinegar (I suppose you could use regular ACV from the store, but I think using the real stuff adds an extra punch. 1 teaspoon Citronella Essential Oil (I found this at my local natural foods store, Mix together in a spray bottle. Apply to the animals frequently (give it a good shake before applying). And be careful, it smells strong. Whew!