Nearly all animal species have sufficient biological equipment for producing an abstract language—they can make sounds, they can gesture, they can rub against one another. With access to some mud, most organisms could write things down.
Almost any physical artifact can serve the purpose of conveying a language, as we humans have by now so ably demonstrated. What the other animals lack is what language represents. For what good is an abstract language when one’s entire world is already present, always in the here and now?
And we humans too—we had nothing to talk about until just so recently.