That's where things get interesting. As soon as you start asking what counts as communication... what about signals passing between cells? What about heat passing between atoms?
As soon as try and draw a firm line between "X counts and Y doesn't", you find that you really can't. There are no obvious boundaries between a deeply complex and fully functioning FL human brain, and a pile of atoms bouncing around arbitrarily.
Or would one count any communication between animals as language? In that case almost any interaction would count.