Hornets' nest

D. got a blanket from the balcony of the top floor and started to unfold it on our regular balcony. Suddenly she jumped away. Two hornets were flying around a "messy" something. I found them big, nearly 3cm, but D. said they were still young.
We discovered a small nest attached to the blanket, with hornets and larvae in different phases of development. My main and the extra show it a bit.
D. helped the flying hornets out of our house into our garden, and did the same with the nest. The blanket then went into the washing machine.
The nest is soft like paper, but the part where it attached the blanket is very hard, more stone than paper.