Consider my Bernese mountain dog, Ruby, when she yelps, whines, gnaws at her paw, limps and then comes to me, seeking aid: I infer that she is in pain because under similar conditions I behave in similar ways (sans gnawing). Physiological measures of pain confirm this inference-injured dogs, just like people, experience an elevated heart rate and blood pressure and release stress hormones into their bloodstream. I'm not saying that a dog's pain is exactly like human pain, but dogs-as well as other animals-not only react to noxious stimuli but also consciously experience pain.
All species-bees, octopuses, ravens, crows, magpies, parrots, tuna, mice, whales, dogs, cats and monkeys-are capable of sophisticated, learned, nonstereotyped behaviors that would be associated with consciousness if a human were to carry out such actions. Precursors of behaviors thought to be unique to people are found in many species. For instance, bees are capable of recognizing specific faces from photographs, can communicate the location and quality of food sources to their sisters via the waggle dance, and can navigate complex mazes with the help of cues they store in short-term memory (for instance, "after arriving at a fork, take the exit marked by the color at the entrance"). Bees can fly several kilometers and return to their hive, a remarkable navigational performance. And a scent blown into the hive can trigger a return to the site where the bees previously encountered this odor. This type of associative memory was famously described by Marcel Proust in À la Recherche du Temps Perdu. Other animals can recognize themselves, know when their conspecifics observe them, and can lie and cheat.
It is a deep dive in philosophical debate and he acknowledges that he's sometimes met with blank stares after making his case, but if you're interested in his intellectual framework for defending the idea of universal consciousness in humans and animals, read the rest of his piece at Scientific American. Whether you agree with his view or not, Koch's piece is another sign that our understanding of our relationship with animals can evolve and adapt as we learn more about the wonders of our natural world.