20+ small black objects in sky above, moving in “figure 8” motion cohesively

From my apartment window, I saw at least 20 small objects moving together cohesively in circular and “figure 8” motions in the sky. They resembled birds in that they were high up in the sky and dark in color. If someone was to glance at them quickly, the objects would not have looked out of the ordinary. Most people would have likely assumed they were birds. I also was questioning if they were birds, until I re-watched a recording that I took and realized the objects did not appear to flap their wings as a bird would.
The objects were so high up (or maybe so small?) that I was unable to distinguish their shape. If I had to make my best guess, they were circular and round rather than square or triangular.
I began to record the objects to show my partner what I was seeing. I thought their motions were strange, the objects seemed to move cohesively together as a unit? A few stragglers would occasionally move much faster than the other objects and go somewhere else out of my sight, but for the most part the objects remained together as a group.