A couple of years ago, we were contacted by freelance photographer Anand Varma for a project he was working on for National Geographic (alas, behind a subscription paywall). Recently, he sent along an instagram post featuring this image. Here's the copy;
"To photograph this Anna's Hummingbird's forked tongue, I worked with a scientfic glassblowing company in Berkeley called Adams & Chittenden who made a custom "hummingbird dinner plate" out of glass. I glued a tiny aluminum wire to the base and angled the camera so it looks like the glass is floating. Finally, I trained this hummingbird in Chris Clark's lab at UC Riverside so it would feed through the tiny opening you see on the right side of the plate"
Check out Anand's hummingbird portfolio, as well as others - it's amazing!