Spiny Norman said:

The Action Lab explores how physical properties like friction, cohesion, and moisture influence granular behavior. By examining why different materials naturally form distinct slopes or spontaneously separate into layers, the experiment demonstrates how manipulating these fundamental forces can defy common expectations of how sand behaves when poured.

https://www.youtube.com/watch?v=G6pTelud5-E

Part of the syllabus for young ant lions.