system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do series like Planet Earth capture footage of things like the inside of ant hills, or sharks feeding off of a dead whale?

Partially I’m wondering the physical aspect of how they fit in these places or get close enough to dangerous situations to film them; and partially I’m wondering how they seem to be in the right place at the right time to catch things like a dead whale sinking down into the ocean? 

What are the odds they’d be there to capture that and how much time do they spend waiting for these types of things?
gpt
some of the series at the end do a brief section about how they go about capturing the footage that they showed.  They make their own custom rigs with various types of cameras to help them get shots. They leave camera 'traps' in places and hope to get lucky with them. They wander around following research or local guides to help increase their chances of being in the right place at the right time. So a lot of it is somewhat down to luck. They will know from research roughly where to go for certain things, but being able to capture specific things is down to luck on whether they get any usable footage in the days they allocated at a site. Depending on what they are looking to film at any given site, the time they allocate will differ.