They are hit and miss. One thing I think you have to make sure of is that there is a licking branch over the top. These situations have always been more productive for me. The nuttiest thing that ever happenned to me with a scrape (I usually try to hunt a scrape line), was one day I had to pee so bad but I didn't want to pee out of the stand so I climbed down and peed right on a buck's scrape and then messed it up with my rattling antlers. A nice 5x5 showed up about an hour later and he went just nuts!!! Snotting and scaping like wild. It was just at the beginning of the rut so I think he was just running stupid and I was very lucky. Dropped him where he stood. It happenned only once but was cool to see.