Trapped: how do you film wild animals?

A good part of the time I spend online is dedicated to watch wildlife videos, I really love to see the passion of so many people in making this kind of movie. It's difficult, time-consuming and often frustrating.

Lately I found a nice video called "Trapped" by Emily Narrow, where you can see the way that most of those films are made, using camera traps:

I think it's way better to watch in full screen: click here.