Potter Wasp Nest

I saw two mud balls in a branch (photo # 3 and 4), about the size of a marbel. From PN I knew they were Potter Wasp Nest. I had never seen one before. Later I found another one "open" and I could see a green caterpillar inside. The nest is mud made of a mixture of earth and regurgitated water. When a cell is completed, the adult wasp typically collects beetle larvae, spiders, or caterpillars and, paralyzing them, places them in the cell to serve as food for a single wasp larva. As a normal rule, the adult wasp lays a single egg in the empty cell before provisioning it.