Camera Trap Setup Part 2

Well no luck.....the only thing I had was the rear end of a deer. But I'm not giving up so I setup my FurFindr and rebaited the site with another good dose of fox urine and beaver castoreum. The FurFindr is a really cool tool which produces short sound bites of four different animals: a bird, fox, rabbit, and a rodent. Each bite plays for 5 seconds and then repeats every 30 seconds. An electronic light sensitive eye located on the outside of the unit allows it to play only at night when predators are most active. They say a human can hear it 300 yards away, so a fox with its superior hearing should be able to hear it even further. The FurFindr should pull them in and then the lures should hold them there in front of the camera long enough to get some photos. I set it this time to the rabbit squeal to see what happens.
Afterwards I went exploring and came across what would be a perfect denning area. The entrance hole was underneath an old root and appeared to have been dug towards and underneath the stump from which it had originated. I wanted to set up a camera nearby, but it is right on the edge of a trail and would leave it exposed to anyone who walked past it. I've already had one camera pilfered so I'm at odds at what to do with such a perfect opportunity. I'm thinking about spreading out a smooth area of sand near the entrance to act as a "track trap" to see if anything is using it as a den.