This is the fourth of a five-part series of blog articles exploring how I can practice non-violence against insects in my day-to-day life:

  • The first post offered some brief notes on insect abundance in artificial turf sports pitches (as opposed to grass pitches).
  • The second post made some rough calculations to estimate the number of insect killed by driving.
  • The third post applies those calculations to a specific decision in my life: choosing which of two soccer clubs I should play at for the 2026 season.

Content warning: This post describes animal suffering.

In the previous posts in this series, I have offered some scientific evidence and reasoning to explore whether two activities — driving and stepping on grass — kill large numbers of insects. My rough calculations (see the third post), which estimated the number of insects killed by driving and stepping on grass in my own life, resulted in estimates in the tens of thousands, hundreds of thousands, or millions of insects.

I think it’s worth pausing here, because that is quite a strong claim. A very routine activity — driving to soccer and having a kickaround with my teammates — is potentially costing millions of lives.

Is that really true?

If my estimates are approximately correct, and these activities are indeed costing millions of lives, then that is big news. If you assign even a fairly low moral weight to the lives of an insect — perhaps in the ballpark of ~1% of the value of a human, as some of my colleagues have tentatively accepted based on [Rethink Priorities’ research] — then this every day activity represents an ongoing moral catastrophe.

Is this everyday, mundane activity really a moral catastrophe? Is having a kickaround in the park really as bad as mass murder?

I think it’s worth exercising caution. Sometimes, when you cry wolf, there is no wolf.

History has plenty of examples of people who thought there was a moral catastrophe when there actually wasn’t. Fundamentalists often delude themselves into thinking that there is something really, really bad happening, when actually there is not. Examples include the decline of a particular religion or set of religious practices; demographic change/immigration; women being granted the right to have abortions; and other social groups receiving increased rights. People have killed others, and continue to kill others, to stop these perceived moral catastrophes. Clearly, this level of fundamentalism involves delusion, not an actual moral catastrophe.

For sure, there actually are ongoing moral catastrophes that most of society don’t know or don’t care about — just visit any slaughterhouse. Eating a bacon and egg sandwich, another everyday, routine activity, really is as bad as murder. Sometimes, when you cry wolf, there actually is a wolf. An unrecognized moral catastrophe also makes for a great plot in the Dr Seuss book Horton Hears a Who!.

But in the case of the bacon and egg sandwich, it’s easy to find the dead bodies. You can track down and visit the slaughterhouse where piglets are killed to produce that bacon, and you can go and see hens actually forced to endure being cramped into tiny cages non-stop for over a year to produce those eggs. Most professional philosophers believe that factory farming is wrong (see endnote 1 here).

What about with insects? In my third post in this series, I gave some published scientific evidence that supports the hypothesis that walking on grass kills insects. But this evidence isn’t conclusive. Nobody has published a study where they systematically look for all the bodies of insects killed by stepping on grass and conclusively rule out all alternative hypotheses (e.g., other causes of death).

What if we applied common sense to this question? If you asked the general public whether they thought having a kickaround in the park is good or bad, most would tell you something like “Sure, it’s good fun” or “Yeah, great way to exercise and make friends”. Some particularly well-informed people might even say something like “While casual sport has many physical, emotional, and social benefits, many disadvantaged socio-economic groups face systemic barriers to participation and to use of green spaces, so it’s important to remove those barriers”. Nobody would tell you “Absolutely do NOT do that, you’ll kill millions of insects! Are you insane?!”.

The general public are wrong about plenty of things. Common sense is definitely not an absolute measure of empirical truth or moral wisdom.

So, we are in a position where we have hypothesized the existence of a moral catastrophe, based on circumstantial but inconclusive evidence, and basically nobody else would agree that this is a moral catastrophe. It is worth being very careful with the strength of claims we can make — there might actually be a moral catastrophe, but it is also possible that I’m deluded and that the common sense view is the correct one.

How can we tell the difference? We need to find conclusive evidence. In the case of factory farming, you can go to a slaughterhouse and see the dead bodies. Likewise, is there a way to obtain evidence about the numbers of insects killed by walking on grass/driving? We would need to demonstrate two things, in a way that is convincing to skeptics:

  1. That there are thousands or millions of insects crawling around in the grass / flying around traffic.
  2. That walking on the grass / driving kills thousands or millions of these insects. In other words, once you’re done walking around on the grass or driving to the shops and back, you should be able to point to those thousands or millions of dead bodies.

If we can demonstrate those two things, then we may be justified in believing that walking on grass or driving constitutes a moral catastrophe. Until we have demonstrated those two things, it is worth exercising caution due to the risk of falling into delusion.