One of the biggest questions in animal cognition is whether animals behave with intent.

The standard assumption for centuries has been that their behaviors are driven solely by instincts, drives, or training. Behaviors that don’t fit those templates are often considered coincidental or accidental, as mistakes that occur while an animal is goofing around. In other words, such behaviors might appear (to us misguided humans) to be intentional—but in the old view, they are not.

Over the past 30 or 40 years, science has made fascinating discoveries about what animals can do. Few of our ancestors would have claimed that elephants stand beside their dead for days, that baboons can distinguish real words from nonwords, or that baby birds babble to learn songs just as human infants babble to learn speech. We know now that seagulls drop clams on hard ground to break them open for food, killer whales carry their dead for weeks, magpies recognize their images in mirrors, and mice respond to suffering in other animals. Add to this collection evidence of ticklish rats, humming bears, surfing goats, prairie dogs with advanced vocabularies, sea lions thinking deductively, and parrots that count.

These examples have been observed at length, and many have undergone rigorous scientific replication. No one would have predicted such riches 40 years ago. And horses are no exception. With mental capacities under-estimated for millennia, these animals display outstanding memories, complex societies, sophisticated silent communication, effective problem-solving, and much, much more. But do they show intent? I think so.

The Story of Mac

Upon moving to a new barn a few years ago, one of my horses in training began to use his halter in a way that strongly suggested intent. Halters were hung on hooks just outside each stall door, within the horse’s reach. This is not uncommon—it helps us to catch a prey animal quickly if we need to.

Instead of living in a pasture 24/7, Mac was now led to the pasture on certain mornings and brought back into a large indoor/outdoor stall at night. Pastures are highly desired by horses—they contain fresh green grass, lots of equine buddies, and room to run and play.

At one point, Mac began to display a new behavior. On the days when Mac was not led to the candy-grass with his friends, he began to grab his halter from the hook with his teeth and throw it into the middle of the barn aisle—a distance of about 15 feet. And he threw the halter just when a human came walking along, so that it landed in front of them as they approached.

Mac’s apparent intent couldn’t have been clearer: “There’s my halter, please put it on me, and let’s go to the pasture.” Of course, that explanation might just be my human desire to ascribe equine behavior to human characteristics, a form of anthropomorphism. Maybe Mac was only playing with the halter out of boredom and accidentally “threw” it out into the barn aisle. Maybe he did this all the time, even when no one was in the barn. Maybe he threw it in the middle of the night, when he had never in his life been led to pasture. Maybe he was only imitating halter play that he had observed in other horses. Maybe, maybe, maybe.

Or—well, what if?—maybe he was intentionally signaling to humans that he wanted them to use the halter to turn him out. I can’t say for sure whether this is the case, but it certainly seems worth testing. The facts stack up in favor of this hypothesis: Mac did not toss his halter at people when he lived in the pasture full-time, nor did he attempt it when he lived in a barn but was turned out every day. No one saw Mac playing with his halter while it rested on its hook. He either left it alone or lifted and threw it with his teeth in one smooth move. No barn staff member ever found the halter in the middle of the aisle upon arrival first thing in the morning, when no humans had been around. No other horse on the premises threw halters at people passing by. And so on.

We know a lot about animal cognition today, but there is so much more to learn. One of the next questions to be studied rigorously is animal intent. And the answers to that question might lead us to unimaginable discoveries.