Do you instinctively swat the spider crawling up your window or the bee buzzing around your dinner table? It may be time to reconsider reaching for the fly swatter.
The researchers from around the world signed a declaration aimed at highlighting animal consciousness and, consequently, how we treat animals. According to these scientists, there is reason to believe that animals possess consciousness—not just animals that resemble humans, but a wide variety of species.
One of the signatories, Jes Lynning Harfeld, a lecturer at Aalborg University’s Department of Culture and Learning, explains:
A long list of researchers and philosophers are stepping forward to say, ‘Alright, we all agree that a dog feels pain and a cat can think about something. But what about a bee?’
Here are some examples of animals that may have consciousness:
Fish Can Recognize Their Own Reflection
For years, researchers have used the mirror test to determine whether an animal can recognize itself. The test involves placing a mark on the animal and seeing if it notices the mark in a mirror.
Until recently, only certain mammals passed the test. However, scientists have now found that the cleaner wrasse, a type of fish, is also capable of recognizing itself.
The question of whether animals perceive themselves as individuals ties into a broader issue that researchers behind the declaration face—how to define consciousness itself.
“The overarching definition we work with is phenomenal consciousness—the idea that a conscious being has an internal perspective, that there is ‘someone’ experiencing the world,” says Jes Lynning Harfeld.
“Alongside that is the expectation of emotional consciousness, meaning there isn’t just an internal perspective but also positive or negative experiences, such as pain or joy.”
One way to understand this is by distinguishing between instinct and conscious experience:
“A plant also does things—it turns toward light and extends its roots toward water. But none of those actions mean anything for the plant. For animals with phenomenal consciousness, actions are experiences.”
Octopuses Avoid Pain
Not only can octopuses feel pain, but they actively seek to avoid it—just like humans.
Experiments cited in the declaration demonstrate this. In one study, octopuses were given the choice between two water tanks: one with vinegar (which causes discomfort) and one with saltwater.
Afterward, those that had been exposed to vinegar were given pain relief. When the test was repeated, the octopuses deliberately sought out the tanks where they had previously received pain relief and avoided those associated with discomfort.
Octopuses are particularly fascinating when it comes to animal consciousness.
What’s interesting about octopuses is that while humans have all their neurons concentrated in the brain, octopuses have theirs distributed—so their brains are also in their arms.
Some experiments even suggest that an octopus’s arms can act independently, as if they have their own brains.
We’re dealing with a being that is vastly different from us, yet it exhibits behaviors associated with pain and conscious decision-making, despite having a brain structure unlike our own.
Bees Enjoy Playing
In a 2022 study, researchers observed that bees rolled around with small wooden balls.
This behavior wasn’t linked to survival or reproduction—so what were they doing?
They were playing.
The study concluded that the bees were engaging in play for its own sake, and that the more relaxed the bees were, the more playful they became.
Play behavior is particularly interesting because it suggests specific conscious states. If an animal functions purely on instinct, we wouldn’t expect it to engage in play.
This type of behavior requires a relatively high degree of consciousness. Until now, scientists assumed that only mammals were capable of such awareness.
However, discoveries like these playful bees have led researchers to rethink consciousness in animals, extending it to include fish, reptiles, crustaceans, and even insects.
Fruit Flies Have Different Types of Sleep
Do you dream a lot at night? Do you prefer sleeping near others? Fruit flies do too.
According to the declaration, researchers have long known that fruit flies experience a form of sleep. However, new studies now reveal that fruit flies sleep best when surrounded by other fruit flies—and that they have two distinct sleep phases: quiet sleep and active sleep.
During quiet sleep, their brain activity slows down almost entirely, helping to reduce energy consumption and stress. But in active sleep—the stage associated with dreaming—their brain activity is nearly as high as when they are awake.
If dreams exist, then there must be some form of consciousness associated with them. However, understanding animal consciousness remains an open question.
With humans, we can communicate and have language—something we don’t share with animals in the same way. We don’t have direct access to their consciousness. So, researchers try to build as much background knowledge and reasonable justification as possible to support their assumptions.
Would You Still Swat the Spider?
If you knew that a spider or a bee had consciousness—and could potentially feel pain—would you still kill it?
That’s one of the fundamental questions raised by the declaration.
If we can substantiate our assumptions about consciousness in a wide range of animals, it implies that they may have welfare—and therefore, suffering—depending on how we treat them.
By broadening our understanding of which animals have consciousness, we blur the line between humans on one side and animals on the other. This forces new research and raises questions we haven’t asked before.
Scientists emphasize that if there is even the slightest reason to believe an animal has some level of consciousness, we must also consider how we treat them.
That’s the next step. If we have strong reasons to believe that animals experience consciousness at a level where they can have positive or negative well-being, then we must factor that into political decisions and actions that affect them.