When I was in my teens, I worked for a while for Fred Webster, a scientist who studied bats. Fred's house was, appropriately, right next to the Mount Auburn Cemetery and his property was so large that he had a gigantic trampoline in its own building and a large Quonset hut (originally meant to be a helicopter hangar) where we worked taking photographs of bat flight patterns. I still have a small scar on my arm from the subcutaneous anti-rabies shots I had to have in order to work there.
The bats I worked with were the little brown bat (Myotis Lucifugus) and one of my favorite tasks was defrosting them. They hibernate well and if you keep them in the freezer compartment of the lab's refrigerator, all you have to do is take them out and let them thaw for a while. I'd go to the lab refrigerator and open the freezer to take out an ice crusted lump and place it in the bottom of a cage. A short while later with the frost melted into a pool around it you could see that it was furry, curled up on itself and small enough to fit in the palm of my hand.
Later in the day it would shake itself awake and climb the wires of the cage to hang upside-down. As I remember we gave them a couple of days to acclimate before flying them.
On one side of the hangar was an expanse of black velvet to provide a non-reflective surface to photograph against. Positioned in front of that backdrop was an electronic cannon that let us fire mealworms into the air to a relatively predictable height. High on the opposite wall was a device called a "gun camera". It was a repurposed piece of military hardware that had been used to track and confirm air combat hits.
We'd release the bat and it would start flying circles around the hangar. When it was in a good position, we'd trigger the cannon and camera simultaneously the bat would dive for the treat and the camera would fire about six sequential exposures in about a second. We used a Graflex 4x5 plate film back. When the plates were developed we'd have a record of the swoop, loop and capture all on a single plate.