Leaf-cutter Bees are a family of solitary bee species, known for the female cutting neat segments from leaves and rolling them into a sausage shape, which they then use to make nest cells in a variety of cavities. This one is probably a male, and so not doing its characteristic leaf-cutting. It is recognised by the white hairs in its front legs (tucked under in these photos) and a pale hairy face. This one may be the Black-headed Leaf-cutter Bee, which is common on coastal dunes in the north.