Carpenter bee

As far as I know carpenters bees are rare. This year I saw they again in the garden of my mother. It's the second year I saw them here and they were in the same area of the garden as last time. I tried to find the nest but I didn't see a bee flew away. They flew the whole time around the same plant. They were really busy and who knows, maybe there were more and I didn't realized that they alternated. By the way I think these little bees are amazing. They were black with a blue or green glimmer. It depends how the light reflects. Sometimes I saw the big black peak on the head. Last time I did photos (link) from the head with the long peak. This time I had no luck, however it was luck to got them for my camera again. I'm happy with the photos. It's not easy to photograph such little insects wich are busy all the time. I hope you like the photos too. Do you know carpenter bees? Where did you see them?