Re: grain bags and deer
We had 49 bags out this year. Ravens, for whatever reason, can smell oats in a bag from 20miles away but don't even take a second look at a canola bag. Really quite wierd. I am told there is an oil in the oats that they can smell (likely BS).
The best and only cure we have found for ravens is to get permission form the local Conservation Officer to shoot some (some people don't realize they are a protected species) as they are doing damage to your crop. One dead raven in the middle of a 250' bag will keep the ravens off for the rest of the year. The trick is to shoot one!! These are the wiliest birds and seem to know when something is up. We had two large oat bags 50' from each other in a field, but only had enough dead ravens to put one on one of the bags. It never had any more damage done to it and the other one was ripped right up. The other ravens will not eat a dead raven. We tried flags and scarecrows (which seem to work OK for deer) but the dead buddy trick works the best.
Putting them as close as possible to busier roads also helps.
We had 15+ tough canola bags and had almost no damage done to them. All in all, if we had put 550,000 bu of grain in piles, we would be cleaning them up for years and would have lost grade on everything. And we got away with storing some tough grain 2 or 3 months before drying, which you would have a hard time keeping control of in the bin (canola up to 15% in bags) .