Why Bugs Might Matter

We all know the children’s poem: “step on a crack, break your mother’s back, step on a line, break your father's spine”. As a precocious child following this advice, I mostly didn't believe that stepping on a crack in the sidewalk would injure my parents. But there was always a risk that the poem was true. I was uncertain about whether it would matter, but I wagered that the inconvenience of avoiding cracks pales in comparison to the suffering my parents would experience with broken backs. So I started to only step between the cracks.

When the possibility of extreme harm is higher than zero, this type of argument helps us establish a course of action in uncertain situations.

Here's another uncertainty: the sentience of bugs—small invertebrates including insects, spiders, worms, and other critters that are ubiquitous on Earth. While the scientific world is generally in unanimous agreement that sufficiently complex non-human animals such as mammals, birds, and fish are sentient, we are less certain about the moral status of more neurologically simple animals like bugs. Let’s outline a wager argument about the sentience of bugs, similar to the one I made as a child.

Consider two possible worlds: World 1, where bugs are incapable of experiencing suffering, and World 2, where bugs experience morally relevant suffering. If it turns out that we live in World 1, then we need not worry about the lives of bugs because they carry no intrinsic moral weight. But, if we are in World 2, how much concern should we have for their suffering?

Let’s say that each bug experiences on average suffering equivalent to f. In World 1, we would have f=0, and in World 2, if 1 is the capacity for suffering in a human, f is likely somewhere between 0 and 1. Let’s consider the implications of different values of f.

There are approximately 10^18 bugs on Earth- approximately 10^8 bugs for every one human - bugs in this case defined as just insects. Since there are approximately 7x10^9 humans on Earth, the collective value of the suffering of bugs is approximately 10^18f / 7x10^9 ≈ 10^8f times that of humans. Depending on the value of f, this could be big or it could be small. If we lived in World 1, f would be 0. But what if we don’t?

It seems unlikely that f is 1 - it might not even be close to 1. But even if f is incredibly small, say 10^-6, that is, the value of one person’s suffering is 1,000,000 times that of the average bug, then the total weight of suffering of bugs outweighs that of humans by 100 times.

The example above shows that bugs might have overwhelming value. Just like how I stepped between the cracks in my childhood, we ought to act as is if we live in World 2. We should wager in favour of World 2 because of the overwhelming suffering that could exist if it turns out to be reality - and based on current evidence we cannot be certain that f=0. This is a bold statement that might contradict many people’s notion of bugs as merely pests. Let’s see what this means for us.

Almost all of our actions impact the lives of insects. In some ways we voluntarily harm them, such as by cultivating the vast majority of our crops using insecticides, and the boiling alive of thousands of silk worms in the process of manufacturing every single item of silk clothing. While our impact on bugs is significant, it would be a mistake to assume that most insect suffering is human-caused. Almost all bugs reproduce using a strategy known as r-selection, involving the birth of hundreds or thousands of offspring of which on average only two are expected to survive if the population remains stable. The others succumb to death by starvation, predation, or disease. If bugs are sentient, the suffering essential to this type of reproduction is unimaginable.

A wager for the suffering of bugs would turn insecticide use and silk clothing into animal welfare issues. It would make us think twice about how we dispose of food and how we maintain our outdoor spaces. However, since the vast majority of insect suffering is likely not human-caused, the main implication would be that we ought to research, advocate for, and eventually implement effective and sustainable large-scale interventions to reduce it.

I know that stepping on a crack won’t break my parents’ bones. However, there is a chance that bugs can suffer, and that their suffering is of immense proportion. We live in either World 1 or World 2. In the coming years, decades, and centuries, we will discover which of these worlds we inhabit. Let’s make sure that if (or when) we realize we live in World 2, we are satisfied that we have a plan in place and are able to do all we can to improve the lives of bugs.






Matthew Allcock