If you see something out of the corner of your eye hovering near red flowers, you automatically think “Hummingbird”, but no, these are Clearwing moths. This one is a Hummingbird Clearwing, Hemaris thysbe.
They are the size of very large bumblebee, with the long curled tongue typical of moths, and they are quite territorial, very much like actual hummingbirds. These two below had a tiff just after I took this photo, and then one retreated:
The two above are a second species, the Snowberry Clearwing, Hemaris diffinis, which has dark rather than pale legs, and two dark stripes on its underside. It is sometimes rudely called the flying lobster. I came across these two mating, flying around conjoined, then settling for a short rest on the grass:
The clear wings are supposedly a consequence of losing the usual scales that cover a moth’s wings, because their flight habits are so energetic, though I find this hard to believe.
To see how they mimic hummingbirds, watch this brief video. If a real hummingbird comes close, the moth flees.
Most moths have small bodies and large wings, but these have huge bodies and relatively small wings, so the initial gestalt is very un moth-like.
I am for some reason reminded of a lovely story about Charles Darwin, told by his granddaughter, the author and wood-engraver Gwen Raverat. They were playing Lexicon, a predecessor of Scrabble. He put down ‘moth’, and she added ‘-er’ to the end. Darwin stared at this mysterious word and said “Mow-ther, mow-ther, there’s no such word as mow-ther.”