A Riddle:

If prodded I'll shout and spit,
But left alone quietly sit.
Another must strike 'fore I lay a blow,
And after I hit I'll back from my foe.
I travel on wheels across the seas,
To speak and trade with enemies.
My brothers also, they have much to say,
With nary a hand we all point the same way.
We'll quip the same jests, and with cunning disarm,
Any strangers that may wish us harm.