Unlike mrbb I've found that deer calls do work. But only on certain occasions. Although I always carry a grunt call with me I only use it sparingly and only from late Oct to mid Nov. And you need to know how to use one and not just blow into it. Two seasons ago after getting into my stand after a rain at 1:00 in the afternoon and waiting 15 mins or so for the area to "calm down" I gave a couple grunts on my tube and use my rattling bag to simulate a fight. A couple of grunts during the rattling and then 2 more after the 30 second sequence. Within 3-5 mins a very nice buck came in to within 30 yards and stood behind a bush for the longest time looking for those 2 buck. He finally came closer and offered me a good shot and by 1:45 I was putting my tag on him. The year prior I had 2 good buck come past me out of bow range and when they got into some cover I let out a long slow grunt about maybe 5 seconds. They came back out and were looking all over but never saw me in my tree stand. They turned and went back into the cover and again I grunted them back out. This went on for about an hour before they finally gave up on looking and disappeared. One of these buck was a nice 8 pt and the other a beautiful 10 or 11 pt. And I hunt exclusively on public land.
Now don't get me wrong. They don't always work. I already grunted at a smaller buck and he took off like a scalded cat. I guess he must have gotten his butt kicked earlier.