I had to clean up in and around a storage shed the other day so the wife can use it for a chicken coop. There was a garbage can behind the shed with dog food in it that I use for bear bait, and the food had gotten wet. I was going to drag it out to a local spot just to lay it out with a camera on it as a scouting event, but multiple disasters still regularly happen here at the house, and I've been denied the time to do anything but wipe asses here. So I dumped it in the swale on the property. The magpies were on it within minutes. Their noses are as good as that of a bear, and the speed of their arrival is much quicker. One would think that they knew that food was in the can, but I never saw them hanging out on the can. But once it was poured out, there they were, almost immediately.