Cool cocoon i found

I washed my patio furniture and i found this in one of the cushions. It's so cool! It's put together so well, made from assorted leaves and completely sealed on both ends. I am assuming that there is some sort of larva in there. COOL! Once i finished cleaning the furniture, I witnessed the little insect that built this. He (or she) is building another one of these things now. It looks like a little purplish/black bee and it brings the leaf sections in one rolled section at a time. YAY.