Probably because there might not be the competition and not the right time of year. In most cases I'm sure there pissing in it, they are just not doing it when you see them. Depends on the age too I think.

I've seen many 1.5 year old bucks in late October to early November with dry hocks. They are horny but they are not sure why and I'm not so sure If they know what to do anyway when they get this way. Some do it and some don't when it comes to 1.5's I think.