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Insects May Be Smiling on the Inside

January 7, 2019
Happy insect (drawing credit: Timmy Gibb)

As a fourth-grader I drew my first real insect in art class. I think it was a pretty good rendering. It was anatomically correct for the most part, right up until the very end when, as children often do, I planted a big ole smiley face on the head, two dots for eyes, a circle for a nose and a big, upturned, half-moon smile for a mouth. Doing so probably made me smile but it did not make my teacher, Mrs. Kessler, smile. She corrected me, saying that insects do not smile. She was right, of course, but over the years I have pondered why insects don’t smile. Or, could it be that they do and we just do not know it?

Anthropomorphism is the assignment of human traits or emotions to non-human animal species in order to make them appear or behave as human beings. To do this is an innate tendency of the human psyche. I drew the picture of a smiling insect because I wanted the insect to be happy, to be more like an emotional human being, so that I could better understand and relate to it. It is a normal and, in fact, psychologically healthy behavior but not one that is particularly useful in science (or in art class).

Useful or not, we humans tend to do this in all of our interactions with animals. We want to see them as emotional beings. Many mammals appear to have emotions like us. One would be hard pressed to see a dog greeting its master and not say it is happy. It seems to express this emotion not with a smile but with other behaviors, such as over-the-top excitement, tail-wagging, slobbering, face-licking and bouncing all over.

So why does a dog not just smile to show joy and save all of that other energy for fetching a paper or slippers or something useful? Can a dog smile? I ask myself if I have ever really seen a dog smile. OK, yes, possibly the dog I saw on the freeway with its head out of the car window. It did appear to be smiling – but maybe it was a wind-induced smile, not really a happiness-induced smile.

We know what a happy smile looks like on the faces of our friends and families, but do we know of animals, other than humans, that can actually smile? And if they do, is some kind of emotion, like happiness, responsible for controlling the facial muscles that create that smile?

In times past, scientists have said “no,” but new thinking is that perhaps they have underestimated the emotional range of animals – particularly domesticated species, such as dogs and cats. New theories by animal psychologists go so far as to attribute primary emotions (fear, sadness, anger and happiness) and even some secondary emotions (jealousy and embarrassment) to dogs. As for cats, they naturally sport a permanently upturned mouth that appear to be a grin. It is risky to identify that as an actual smile because it never changes, whether the cat gets to eat the bird or not. So what looks like a smile can be deceiving – cats may not be smiling at all. Try to tell that to cat lovers.

If we have trouble interpreting emotions in one or two species, such as a dog or a cat, what sense can we make of insect emotions? Insects species outnumber mammals by about 1,000 to one.

Most entomologists agree that insects do not feel emotion – at least, not in the same way that humans do. Their brains are too simple, missing the key parts associated with emotion in human brains. There may be some level of awareness in insect consciousness but not to the extent of feeling attraction, or empathy or happiness or sadness or even the ability to feel joy or pain. To say that an insect is happy or sad or angry is not necessarily accurate because we don’t know exactly what is going on in their little brains, and until they learn to speak, or write or communicate with humans more effectively, it is a stretch to assume any emotions. But the idea of insect consciousness, however minimal, cannot be discarded out of hand.

A lot more behavioral research would have to be conducted before scientists could positively conclude that there are – or are not – the beginnings of emotions in insects. But here is a start. Consider, for example, that many insects display behaviors that appear somewhat similar to what we recognize in ourselves. If you agitate their nest, wasps can appear angry. Grasshoppers can become nervous (if you try to catch them and miss, a second attempt is usually futile). Flies can be frightened away. Ants can show attraction, and house flies appear to be curious. So, given this, who is to say that an insect can or cannot be happy? Could we know if only we were able to get inside an insect brain?

Believe it or not, some laboratory scientists are doing just that – monkeying around inside insect brains. This is what they have found: When certain sections are cut out or dissected, insects show altered behavioral responses, such as where and when and how they move, and these behavioral responses are predictable, just like in humans.

In addition, we have long known that insects detect and respond to intraspecific pheromones – changing their behavior markedly. But what we are learning now is that insects respond to brain chemicals in a manner similar to humans. If existing chemicals are modified or artificial ones introduced, insects respond accordingly. For example, dopamine, a neurotransmitter that plays a role in human pleasure and reward pathways, is also present in insect brains. When dopamine levels fall in people, symptoms such as depression, mood swings, poor attention and food cravings can occur. When dopamine is inhibited in insects, their behavior also changes drastically and becomes erratic. Interestingly, we have learned that if dopamine-deficient flies are treated with valium – a commonly prescribed treatment for panic and anxiety in humans – they seem to find relief and respond in much the same way that human patients do.

Does this mean that the small brain of a fruit fly might have the capacity to show preference for a ‘feel-good’ drug … and if so, could it remember the positive experience? If these are both possible then might we conclude that such positive memories could make the insect feel, well … happy?

Interesting hypothesis, but the bottom line is that we really don’t know, and might not be able to know because we don’t know how to interpret an insect’s emotion – if they have one. Until insects learn to communicate better with psychiatrists in the laboratory, we won’t know how to decipher what the insect is feeling.

Motivational speakers often quote statistics from human anatomy regarding the number of muscles that are used to make a human smile compared to the number used to frown, theorizing that it is easier to smile than to frown. We agree that it is better to smile than to frown, but the supposition about number of muscles required has been debunked. Nearly the same number of muscles are used in either case.

What we do know is that the muscle flexing that may result in a smile on a person will always remain hidden in an insect. The difference is due to an exoskeleton.

One of the cruel acts of evolutionary development is that nature has given insects an exoskeleton. Unlike mammals, insects lack an internal skeleton of bones to provide support and allow for movement of the body. Instead, a hardened outer body covering, we call it an exoskeleton, provides for these needs. In addition, having the skeleton on the outside of the body protects internal organs from damage and from drying out. These benefits help explain why an exoskeleton is an advantage for some things but having a skeleton on the outside of a body is a disadvantage for others. A permanently hardened face prevents things that humans recognize as emotions, such as a smile.

Insects can’t smile, but it’s not their fault any more than it was the fault of my fourth-grade teacher, Mrs. Kessler, who we called Fossil Face Kessler because she was incapable of smiling. It is because inflexible exoskeletons make faces rigid.

For all we know, insects and Mrs. Kessler may be smiling for all they’re worth – just on the inside.

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