We had a HUGE brush pile in our backyard. I don't know if you can tell from the photo but it was about the size of our family van. It contained about 25 years worth of accumulated tree branches and leaves as well as some old building materials such as broken bricks and fencing. We had to have it removed because, not only was it an eyesore, but a family of skunks were living in it much to the detriment of our dog who got skunked three times last summer. That was three times too many, believe me.
After getting several quotes we found a company to do it for a reasonable cost. It took them nine hours of hard work. We thought it would make the yard safer for the kids but it actually uncovered tons of sand that we didn't know was under the brush. Animals have burrowed under the sand so much that if you step on it you will sink down! Hence the reason for the sticks that remain. So while the yard looks cleaner it still isn't where we would like it to be.