It's on one of my friends's apartment windows.

We didn't see any bugs crawling/flying around it but not knowing what it is or what might be inside it, we are not touching it or disturbing it.

I Google for images of insect nests (spiders, ants, wasps) and none of the results look like it.

Thank you.

Thanks ^^^ F4U. That's not good to have is it? Should he have professional exterminator to deal with it?

Nah, just get some wasp and hornet spray.

Once you e killed it, you will be surprised at how difficult it is to clean that off. Initially parts break off easily, but then it gets tough. Stains whatever it is on.

I had one of those grow as big as a basketball at my parents home shortly after they passed away. In my case I had some beehive volunteers (honey harvesters) come over to exterminate the hive because these types of wasp kill the bee´s that we harvest honey from. Something like that, cuz I am not sure If they are the same wasp we are talking about.

Can´t really see It that good but It was big as hell...

That's scary, RedOne.

I don't like stinging biting insects.

I had a horrible experience with bees when I was 8: 2 classmates and I ended in the hospital.

So, how did you make out with that ?

Yes Sir!

I meant to update this but I've been busy with finals week. A couple of times I tried to come here and it wouldn't load.

My friend call his landlord and they send out pest control that check all the buildings and found other nests on the other buildings but they turn out to be all empty .

I wonder if there's a specific time of the year those hornets or wasps are more active building those nests and flying around coming going from them.

The nests turning out to be empty, I wonder where they go. Do they build nests elsewhere or do they "fly south" like birds too.

They die. Invertebrates don't have long lifespans, especially in the adult phase.