They came over again and filled a couple of waste bins and a couple of waste bags. They also scared me by climbing up onto the "treehouse" in our backyard, which is little more than a rotting platform, and trying to pull down a very large dead limb from the tree. Luckily, neither of them fell, but I was regretting not having my camera handy to get pictures of them.
They discovered that a portion of our backyard is old branches in a wild pile that's now covered in ivy and blackberry. I think we need a wood chipper to get rid of that, and I have no idea how we'd go about borrowing one.
They really want to bring in a bunch more guys and pull all the ivy and blackberry out, but I'm not sure how many guys they will round up for the job. If they do, though, they can make a serious dent in the chaos.