I always marvel at the neat, round holes in the rose leaves... precision cut by leafcutter bees.
At the bottom of the picture below, there is a leafcutter bee nest which was removed intact from a hole in a barn board. Notice the various leaf pieces which are fashioned into the cylindrical nest-lining. One of my children placed their finger in the photo for scale.
The other object in the picture above, is a cross-section of the leafcutter bee's nest material which shows part of a leaf-liner containing the mixture of pollen and nectar she places inside her leaf-lined tunnel. The white "grub" is a leafcutter bee larva which had been feeding on that yellow/orange pasty mass of pollen.
If we would have some solitary bee nesting tubes mounted in a bee house
in our backyard, I reckon it would be easier to observe and photograph these interesting bees.