Squirrel nest construction
Check for:

https://www.youtube.com/watch?v=6uKDpHM-OsI
https://www.youtube.com/watch?v=3jPtZByr740
https://www.youtube.com/watch?v=Kh1HnMFolgw
https://www.youtube.com/watch?v=M5dduAX8iuI

The third one was filmed by BBC. The fourth one is a closer look of the nest complemented with a fairly good analysis.
The first two are reasonably good, but the third one is just awesome for your purpose!