Here's amateur video of the UFO spotted over Mexico City the other day. As you'll see, a dog barks repeatedly as the craft passes overhead. Also, as the National UFO Center is quick to point out regarding this story, there was a big earthquake in Mexico the next day. Proof of extraterrestrial life, or what?
Here's a "capture."
By the way, there are round, saucer-like unmanned aerial vehicles (a.k.a. drones). I'd source these, but it would save a lot of time if you just Google "round drone."