They are slightly smaller than a hummingbird but they sip the nectar from deep, tubular flowers and hover mid-air almost the same way like the birds. We are very happy to see one or two every summer in our yard. The Hummingbird Moth would not go to a hummingbird feeder, at least I have never seen one doing it. Unlike most other moths they are day-flying insects and mimic the hovering flight and appearance of hummingbirds.
All images: Nikon Z6 III, Nikon NIKKOR Z 100-400 mm f/4.5-5.6 VR S,