Leaf cutter bee on rose

Well, not so much the bee, but this is what they do to leaves of various species of plant. I have seen them on roses mostly, but they also take pieces of leaf from passionfruit, crepe myrtle and even rhubarb!

 They roll the little circle or semi circle up and put it in ahole then lay an egg and put in some pollen for the baby bee larve to eat when it hatches. Cute, huh.