Hi Pig Slayers of the world

I came across a nice group of pigs on Sunday but they ran after I missed my shot[:@]. Today (tues.) I went back and they were down wind and bolted. I want to go back but dont want to scare them away. Seems like they come around this area 1 or 2 times a year ??? Any idea's ?? Ive bein slipping in really quitely trying not to give them much reson to leave . Thanks all for any ideas, theories and input