Bob cats take a long time as a rule ( like any thing there are exceptions ) I have seen them out a 1000 yards just set and look twitching their tail for 10 or 15 min. . Then get up and slowly walk a few to a 100 yards closer and do it all over again or just come creeping in all the way . A general rule of thumb is they don't like the volume very loud if you have it too loud and you have fresh snow you will see their tracks behind you when you leave the stand . Like fox most like higher pitched sounds . Quite often when you have been on a stand for 30 min. you will notice a slight movement and what you may think is a new rock , a cat will be crouched down watching you and the movement you see is the tail twitching . I have watched cats walking in to the call taking an hour or more to get to where you can shoot them but then I have also had them jump down off of a cut bank and land beside me as well. One day in 1998 I saw a large male cat come up from the back side of a ridge out around 500 yards . I turned the volume down and let the puppy squeaks just play . It took him 45 min. to come into about 25 feet of me . He then sat down and watched me for another 10 or so min. His eyes were locked onto the fox pro the whole time and each step was slow and cautious both front and back feet . I saw him a couple of times start to put his foot down then stop and move it sideways or back ward some before setting it down . Time means nothing to them .