I use the pendulum for many years now, especially to make energy maps of lands before building and detect the earth grids and geopathy.
It is just a tool, the answer comes from our body, I wouldn't mix entities with this, or ask who is moving the pendulum.
It works exactly as muscle testing or kynesiology.
Helps us become aware of what our body detects and feels.
For more about it:
www.whitemagicway.com/dowsing.html