I actually don't care at all if an insect lives or dies. Insects do not have emotions; no other insects mourn if one dies. This makes them markedly different from humans and other animals; insects are little more than machines and from a moral perspective much closer to bacteria than, say, mice.
The only reason I care is because of the broader ecological effects. I don't care whether my gut microbes live or die either, if it wasn't for the health effects it would have on me.
I know what you mean. The foundational support beams on my house are starting to rot away. I don't care how they feel, but I hope my house stays upright.
Ants also have a complex range of psychological responses. (Not sure I'd call them "emotions" since we're obviously too distantly related to them to have a meaningful reference here, but whatever.)
Ants have very interesting learning behaviour, but I don't think you can really say they're "smarter" than a mouse, or even "intelligent" (depending on your exact definition of that). You can teach a computer English better than the average human (see e.g. Grammarly), but that does not make the computer smarter. The learning behaviour of ants is certainly amazing, but very limited in scope.
Ants can response to their environment, but are they even "psychological responses" or just a piece of machinery responding in a pre-programmed way? When I played the Sims 20 years ago my characters would respond in certain pre-programmed ways. None of can truly know what it's like to be an ant, but given the tiny size of their brains compared to higher animals I think it's fair to say the machinery for any kind of emotion just isn't there.
> or just a piece of machinery responding in a pre-programmed way?
Is a mouse responding in a pre-programmed way? I'd say you're just showing mammalian bias here.
> given the tiny size of their brains compared to higher animals I think it's fair to say the machinery for any kind of emotion just isn't there
First of all, a whale isn't necessarily smarter than a monkey just because it has a much bigger (physically) brain. Secondly, an individual ant really isn't, because genetically the ant colony is a single unit.
All life is to some level – including your and me – but that doesn't mean there aren't distinctions.
> a whale isn't necessarily smarter than a monkey just because it has a much bigger (physically) brain
I claimed that brain size is deterministic of intelligence, but it's not as if any brain of any size can do anything; there are real physical limits here. Ant brains are tiny, and ants are probably the smartest insects: others have even smaller brains.
Either way, I'm mostly interested in the emotional experience of insects and other animals, rather than intelligence. I think that's a more important factor in deciding whether inflicting harm is morally acceptable or not.
Mice, of course, are also not especially clever or have rich emotional lives in the same way that a dog or pig might have, but there does seem to be some of it, whereas I'm not seeing any in ants or other insects.
I keep an ant colony as a pet.
Ants are pretty much indestructible creatures from a physical point of view - they need infinitesimal amounts of food and water to survive, they don't get sick or hurt, but they're very succeptible to stress. They're nervous creatures and go nuts from stress, acting in illogical and even suicidal ways.
Is it because their primitive brains go haywire? Or is this just our mammalian prejudice speaking? Who knows.
Probably best not to anthropomorphize any animal, I think.
Insect populations are declining in places like New England and the upper midwest despite farming both declining and finding more efficient ways to use fertilizer and pesticides on the same timeline.
If we're going down the road of human introduced chemical toxins (like pesticide pollution) I think a fair bit of blame also deserves to be laid at the feet of the state (and by proxy voters) for poisoning the soil immediately adjacent to roads (and to a slightly lesser degree, the watersheds) with various salts.
When 0.1% of humans dies of a virus, we call it a disaster. When 50% of insects dies, we don't give a damn.