Death is the one experience in life that every human being will inevitably go through. No matter who you are or where you’re from, the end of life is a shared reality for all of us. Yet, despite its universality, death remains one of the greatest mysteries known to humanity. It’s a subject that we all think about at some point, but it’s also something we tend to avoid discussing in depth. The fear and uncertainty that surround it are largely due to our instinctual dislike of the unknown. People naturally want answers. We want to understand the world around us, and death, with all its unanswered questions, challenges our sense of control. That’s why it frightens so many—because it feels like stepping into darkness with no map.
Still, as science and research progress, we’re beginning to shine a little more light into that darkness. While the full experience of death may remain beyond our understanding, certain phenomena surrounding it are slowly becoming clearer. Some of the things that once seemed too eerie or “supernatural” are now being studied and explained with real scientific evidence. Among these phenomena is the idea that humans, like animals, can actually detect death—sometimes without even realizing it. This isn’t about seeing or hearing anything unusual. Instead, it has to do with our sense of smell and how our bodies subconsciously respond to certain chemical signals.
What many refer to as a “sixth sense” may in fact be a combination of evolutionary survival tools, sharpened over thousands of years. Science is now catching up to some of the instincts our ancestors may have always relied on. According to researchers, when a human being dies, their body begins to break down almost immediately. This process of decomposition releases a chemical compound known as putrescine. It’s a strong, foul-smelling substance that signals the start of decay. What’s fascinating is that humans have the ability to recognize this odor—even if they aren’t consciously aware of it. It seems that our brains are hardwired to respond to the scent of putrescine as a sign of danger, death, or something to avoid.
Arnaud Wisman from the University of Kent’s School of Psychology and Ilan Shira from the Department of Behavioral Sciences at Arkansas Tech University have conducted research that supports this idea. Their findings suggest that humans respond to the smell of putrescine much like other animals do—by instinctively withdrawing from the area. This kind of reaction is a deeply rooted survival mechanism. Across many species, the scent of decay acts as a warning signal: something nearby has died, and the area could pose a threat due to predators, disease, or other dangers.
In several experiments, Wisman and Shira exposed people to the scent of putrescine and observed their reactions. The results were clear—those who smelled it, even without knowing what it was, tended to move away, feel anxious, or become more alert. Their findings were consistent with how animals behave when they detect a similar scent. It’s as if our subconscious tells us, “Something’s not right. Get away.”
Interestingly, we’re not usually aware of how much scent influences our thoughts, emotions, and behaviors. As the researchers pointed out, we often don’t know why we feel a certain way about someone’s scent, and yet it can have a powerful effect on how we perceive others and our environment. This idea isn’t new when it comes to sexual attraction—pheromones, which are odorless chemical signals that trigger mating behaviors, have long been studied for their effects on human behavior. But in the case of putrescine, the message is the opposite. Instead of drawing us in, it pushes us away. And unlike pheromones, we don’t need to be consciously aware of it to react.
Some researchers have argued that it’s hard to think of a smell as frightening. After all, we associate fear more with things we see or hear. But when it comes to survival, the nose plays an important role. It silently gathers information and sends signals to the brain, preparing us to either stay or flee. And while we may not associate scent with fear in our everyday lives, our bodies clearly do. The smell of putrescine, even at levels we can’t consciously detect, can make us feel uneasy or on edge—often without us knowing why.
This understanding opens up fascinating possibilities about how human instincts continue to operate below the surface. It’s incredible to think that our brains might still be tuned into warning signs from our environment in ways we barely understand. We often think of ourselves as modern beings, far removed from our primal ancestors. But this research shows that, in some ways, we are still deeply connected to those ancient instincts that helped our species survive.
The idea that our sense of smell could alert us to death or danger—even without our awareness—is both eerie and remarkable. It serves as a reminder that human beings are complex, and our bodies are constantly processing information in ways we don’t always recognize. What feels like intuition or a “gut feeling” may actually be the result of chemical signals and evolutionary programming working in the background.
Learning how our subconscious minds respond to these cues can help us better understand ourselves and the world we live in. It shows us that while some mysteries of death may never be fully solved, we’re slowly uncovering pieces of the puzzle. It also reinforces the idea that science and instinct don’t have to be opposites—they can work together to explain things that once seemed beyond our grasp.
So the next time you feel a strange sense of unease in a certain place or around a particular situation, it might not just be in your head. Your body could be responding to something you can’t see or name—something that’s encoded deep within us for survival. Sharing this discovery with others might just help more people appreciate how incredible and mysterious the human experience really is.
