Swarm of jet-black spheres near Lake Erie darting around in broad daylight.I have a similar sighting from one in Toronto. I thought they might be buzzards or black balloons caught in an updraft. Too freakin weird though. We were driving in a restricted lane construction zone southbound and I started looking around because our two 3G devices jammed simultaneously. The jammed phone is my camera, otherwise I would have photographed them, even though they disappeared after 10 seconds. Saturday evening on I-75 just south of the I-280 ramp, east of the highway over some industrial buildings or perhaps further away, looking over near the old Jeep Parkway. 20 -30 swirling and darting jet-black spheres slowly rising like a moving swarm. In the foreground I saw birds of similar relative apparent size that were much closer. My thoughts went from birds, to balloons, to "I don't know what they could be besides balloons, it must be a tangle in the wind". I called attention to them, and looking back, they were gone. I thought maybe the! y were obscured by clouds, but the way they moved it didn't make sense already because there was minimal wind at the time.