by talking to each other
They talked to each other.
by speaking to each other
Telepathy
it helped people communicate with each other
they wrote letters to each other. And they would talk to each other.
Insects communicate with each other by sensory.
The Egyptians used the Nile river to push sailboats to transport goods to each other and to other.
I do not know how Jaguars communicate with each other. They might growl or purr.
The same way anybody else does.
by pictures scratched out with stones
Social Change A+
They communicate by talking to each other