I had one several years ago too, and I had similar findings that TK had. It was picking up heat sources in the pine trees and the even the oak brush. I even tried it when we were tracking a deer shot in the evening time in the Kaibab, we knew there were a lot of coyotes around, so we oppted to find it and not let the yotes get it. That stupid thing wouldn't even work when it was really cold out. IMHO, keep your money and buy some of that blood trailer spray that will pick up blood that is very hard to see. I used that one time at night and that was the only way we found the deer. Very little blood on the ground, bled out inside and gut pushed out the hole closing it off. We were spraying that stuff and it would pick up little traces of gut. Cool stuff IMO. Later Muledeernut