When Nature Calls is a location-based challenge in Hero's Pass. This challenge is worth 1 Badass Rank.
- In the beginning of the level. This toilet is located next to the helo pad across from the vending machines.
- Past the gap in the bridge, there is a grinder Southeast of a Hyperion 'Emergency Supply Cache'. The toilet is in a container between the building and the nearby grinder panel (above, on a ledge).
- In the last area to the Southwest. There is a lone open structure with a toilet next to two crates and a shipping container.