Leaf Cutter Bees

I've never really given any thought to the odd cut out shapes that appear on the leaves of the roses - until this week. We saw something on TV about leaf cutter bees, how they cut discs out of leaves (they particularly like roses), which they then glue together using their saliva, in order to make individual cells for their larvae.

These bees are solitary, feeding on pollen and nectar. They live in holes in walls, dead wood or old plant stems and from April to August their sole purpose is to produce these cells.