My freshman year of college I was living on the 4th floor of my dorms. It was winter time, and there was snow on the ground.
It was probably around 3 or 4 in the morning and my roommate and I had both randomly woken up but we weren’t talking, as we both thought the other was asleep.
Then we both heard very clear, loud knocking on our window. 4 loud knocks that you could just tell was on glass.
We both said “did you hear that” and were kind of spooked. 15 minutes went by, nothing happened. I was starting to fall back asleep and there it was again, four loud knocks.
At this point I was shaking because in my mind, someone had somehow climbed up to our window and was trying to scare the shit out of us.
So I got up and pulled our blinds back to look for someone, no one was there. No footprints on the snow on the ground, nothing. So I got back in bed.
Another 5 minutes or so and we heard the knocking again but it was coming from what sounded like the neighbors window.
Sure enough we heard our neighbors say “dude, what the fuck” and shuffle around a little. Then like two minutes later, it sounded like every single window on our floor was being knocked on for about 7 seconds straight, just absolutely insane.
People started screaming and we could hear people opening their doors and running across the halls into their friends rooms because they were terrified. It kept happening for probably two more hours but only at specific windows like every 15-30 minutes.
Every time I was about to fall asleep it happened again. I even texted my boyfriend, who lived on the first floor, to ask him if he also heard this, which he didn’t. That was a very long night. No one ever found out what that was, as far as I know.