Have you ever seen a large insect hovering over your brightly-colored summer flowers? It may be a hummingbird moth. My phlox is especially gorgeous this year, the flowers a beautiful vibrant deep pink shade, and the hummingbird moths are all over them (as well as are a variety of butterflies).
Here are some photos. I’m going to plant more of the phlox in the fall so next year I’ll have even more moths and butterflies. Unfortunately, the flowers last only 6 weeks or so, but they are so intensely gorgeous during bloom that I forgive them this flaw.