I got into my elevator a few minutes ago to do some laundry. Two men entered from the 13th (!) floor. They were about sixtyish, in work jackets. One wore glasses and carried a strangely shaped black cloth satchel. The other had a protruding forehead with a few wisps of hair, and a hoodie under his work coat. He stared at me for a full minute, then was silent, then made a few wet chirpy sounds with his lips. Just before we left the elevator, they had a brief conversational exchange that I was hoping was some Slavic dialect. It wasn't. I don't know what it was.
I am fairly sure they were space aliens who need more practice passing as humans.