[forgotmypw38]

Why do people always try to separate certain qualities or behaviors as being "human only"?

[oliveshell]

I don’t think anyone’s doing that. No one here would argue, for instance, that animals don’t communicate with each other.

The difference is intent: when we use the term “communicate“, there is an implied intention to convey meaning that simply can’t exist for an inanimate object like a sand dune (as far as we know, anyway).