A mature buck that comes across a feeder for the first time is going to be nervous, he'll know something's not right. Big bucks can and do get perfectly comfortable around feeders, if they are there all year round year after year, and aren't hunted too much over them. You can go on a few web sites and watch video feed of monster bucks in Texas coming to a feeder like clockwork. Every time they go off, they come in just like livestock.