Even though they are inanimate objects, sand dunes can 'communicate' with each other. A team from the University of Cambridge has found that as they move, sand dunes interact with and repel their downstream neighbours.
https://phys.org/news/2020-02-sand-dunes.html
* water flow * sand dunes * sand * dune * Image: North polar dunes on Mars * journals.aps.org/prl/accepted/ … 89362b45368045733790 * Physical Review Letters