Fear the Little Guy: Why We Fear Certain Small Animals

Brooke Thacker, Nate Willis, Sarah Caplan, Kim Davis, and Nick Hatfield

Why do people get so worked up over bees and spiders? And snakes and rats? Some people are even afraid of adorable squirrels. It’s not like most of us have been constantly badgered (no pun intended) by these critters to the point of dislike or fear. And thanks to modern medicine, even if we do actually come across some of the more dangerous little guys in that list, our chances of survival are very high. But sadly, this was not the case for our ancestors, who were recurrently plagued by these small animals.

Because their survival depended a lot more on avoiding the danger of deadly bites, the spread of disease, and poisonous stings, our ancestors had to develop ways to avoid these seemingly harmless nuisances (granted, snakes are pretty intimidating). Evolutionary psychologists theorize that in order to deal with these threats, we have developed psychological adaptations to help avoid the dangers small animals might present to us (mainly through running away), as we'll discuss in more detail below.

What Are Phobias and Why Do We Develop Them?

The general definition of a phobia is “a fear that is wildly out of proportion to the realistic danger, is typically beyond voluntary control, and leads to the avoidance of the feared situation”. Phobias in and of themselves are not thought to be particularly useful, or to have evolved for a purpose, but fears certainly have been. It is hypothesized by evolutionary psychologists that we have developed predispositions to fear certain things that were harmful to our ancestors. Phobias are thought to be a byproduct of those predispositions.

The table below presents a list of common human fears and adaptive problems (or, things that commonly caused harm to our ancestors) to which these fears have been hypothesized to have evolved. You'll notice that small animals occupy several spots on this list.

Table of Commons Fears and Their Adaptive Problems

Subtype of Fear	Adaptive Problem
Fear of snakes	Receiving poisonous bite
Fear of spiders	Receiving poisonous bite
Fear of heights	Damage from falls from cliffs or trees
Panic	Imminent attack by predator or human
Agoraphobia	Crowded places from which one cannot escape
Small animal phobias	Dangerous small animals
Disease*	Contamination
Separation anxiety	Loss of protection from attachment figure
Stranger anxiety	Harm from unfamiliar males
Social anxiety	Loss of status; ostracism from group
Mating anxiety	Public rejection of courtship attempt

*Small animals such as rats can carry diseases

Though you might not typically think of small animal as being life threatening, there are specific animals of smaller stature that have been recurrent threats to the lives of our ancestors, and as a result, we still show fears of these animals today. 

Snakes (a given), spiders, stinging insects, and other animals that may contain some kind of venom or poison are dangerous to our prospects of survival and reproduction, which is supported by a study covered by Natural Geographic, conducted by the psychologist Arne Ohman, who works for the Karolinska Institute in Stockholm, Sweden. The results of the study indicate that “mammals developed the perceptive ability to focus on things seen as threatening, such as snakes and spiders, and to respond emotionally with a feeling of fear”. 

Ohman and colleagues' evidence indicates that it is easier for people to be conditioned to have a fear reaction to "old threats" like snakes than to "new" threats, like guns. This probably also explains why getting into a car accident typically doesn't leave people with a lifelong phobia of driving, but a single dog bite can easily promote a lifelong fear of dogs.

Over the Hedge: "What if we have a potential pandemic on our hands, vermin running loose, spreading disease and lowering our property values?"

Which Animals Do We Fear the Most?

A study conducted by James Bennett-Levy and Theresa Marteau measuring the self-reported fear of U.K. citizens towards small animals confirms that small animals rank highly in the list of humans' most common fears. Participants were asked to rate a multitude of small animals on a scale of fear and on a scale of willingness to go near these animals.

Results showed that participants across the boards showed an overwhelming fear of rats, and that most women held substantial fears of jellyfish, cockroaches, ants, moths, crows, worms, beetle, slugs, mice, and spiders. 

In addition to the fear and proximity scales, participants were asked to rate each animal in terms of ugliness, sliminess, speed, and sudden movements. In these categories, both sexes showed significant similarities in how they rated each animal in each category, suggesting that humans have innate evolved mechanisms pertaining to different animals.

Additionally, a study conducted by Graham Davey, published in the British Journal of Psychology, measuring a sample of adult’s fear of certain animals gives us an idea of what we consider to be the most dangerous (and thus fear-inducing) small animals. The survey’s results show that snakes, wasps, rats, cockroaches, spiders, and maggots (in descending order) elicit the most fear. The survey also included larger animals, such as horses, cows, and pigs, all of which ranked lower on a fear scale than snakes, wasps, rats, cockroaches, spiders, and maggots. 

From this survey, we can infer that snakes and spiders would’ve been harmful to our ancestors due to their ability (in some cases) inject humans with deadly poison, while rats, cockroaches, and maggots, as demonstrated in the previous study, ranked high in ugliness, which may be a possible by-product of disgust in order to avoid possible contamination by microbes. Fear of wasps may be a direct innate association with the fear of being stung, which can sometimes have lethal consequences.

Caddyshack: "To kill, you must know your enemy, and in this case my enemy is a varmint. And a varmint will never quit- ever. They're like the Viet Cong - Varmint Cong. So you have to fall back on superior intelligence and superior firepower. And that's all she wrote."

Are We Born Afraid of Small Animals?

People are born with an adaptation that allows us to quickly learn to associate certain stimuli (e.g., a spider) and specific responses (e.g., terror), which helps with survival. In other words, it's easier for us to learn to fear things that posed threats to our ancestors. This idea is called biological preparedness. People are not necessarily pre-programmed with a fear of small animals, but even one direct experience with a snake or spider would be enough to cause a person to develop a fear of either creature. 

We can also develop these fears through social learning. Observing someone else get bitten, stung, or catch tuberculosis from a nasty looking sewer rat--or even just seeing someone else's fear reaction to an animal--can cause us to develop a fear of that little creature.

Since we are not born with the actual phobia, young children are more likely to pick up a spider or mouse than an older person, but they learn quickly through direct or social learning which creatures should be avoided. Thus, these fears are learned, but innate mechanisms make certain things easier to learn than others, and help us to learn and remember particularly important things that we should fear.

Would you pick up this little guy?

Conclusion: Is Our Fear of Small Animals So Irrational After All? 

The fear of small animals (microzoophobia) may seem irrational on its face, but as discussed above, our ancestors were given reasons to fear tiny critters. Many animals can carry and transfer diseases, like rabies, through a single bite. There are also historical examples of how devastating small animals can be. Rodents were major players in the transmission of the Black Plague, which is estimated to have killed as many as 200,000 people.

Reasons such as these may have caused humans to adapt a fear of small animals. Those of our ancestors who felt aversion to creatures that reliably caused humans harm were likely to be more successful at surviving and reproducing than those who enjoyed cuddling up to venomous or disease-carrying creatures. Therefore, adaptations like fear and disgust evolved to help us avoid disease, poisoning, or possible mauling that would have recurrently harmed our ancestors’ chances of survival.

 

Monty Python: "That's the most foul, cruel, and bad-tempered rodent you ever set eyes on!" 

Be Afraid, Be Very Afraid

Throughout human existence there have been threats to the survival of our ancestors, including the threat of specific small animals and insects. Snakes, spiders, rats, and many other smaller creatures endangered our ancestor's ability to survive and reproduce. Due to these threats, we developed adaptations to easily develop fears of specific small animals in order to avoid the dangers they presented. 

Experience plays a role in making us fear things. However, we are evolutionarily predisposed to get the heebie-jeebies when we see that random rat or stray spider--and less predisposed to fear newer things that are actually more dangerous to us in the modern world, like guns. 

Even with modern medicine, we are not entirely immune to the potential danger that some animals pose, so it's probably not a bad thing that we still have this fearful predisposition. So, next time you come across a small critter like a mouse, cockroach or a spider, thank our ancestors for that fight-or-flight response because that’s what is preventing a deadly bite or possibly contracting a disease.

How could you fear something so cute?