Our household kills them as do the households of my brothers and sisters. I guess you just don’t know the right people.
I don’t kill any bugs. I carry them out of the house.
In rural Thailand, people may give you funny looks if you kill any harmless insect. Many will ask a monk for permission, even a ceremony, before removing a beehive.
Yesterday we found a very large Asian Forest Scorpion (Heterometrus, แมงป่องช้าง) in our carport, just outside our kitchen door. We notice a scorpion perhaps once a year; but this one was by far the largest we’ve ever seen on this property. We trapped the scorpion into a glass jar, and left it overnight.
By coincidence(?), one of my wife’s best friends is dying in a Bangkok hospital. We also have an old dog who’d been very ill, still not fully recovered.
The next morning my wife took the jar into our orchard and freed the scorpion.
I haven’t seen a ladybug in my house since I’ve lived in Florida. I’ve seen spiders occasionally, and I don’t kill them, which explains why I never seen any other insects. But there’s a debate raging in GD asking whether or not that makes me responsible for the murder of flies, though 
Not unless you kill them.
The Asian bastards do.
Why would you kill anyone or any creature except for good reason ? A tiny proportion of the insect species may be directly harmful, but even then it’s nicer only to kill those that are actually a danger.
Same with humans.
Down in Devon woodlice can be called either ‘chuggypigs’ or ‘slaters’, the latter presumably since they like lurking under slate ( such as roof-tiles ).
They seem almost laughably harmless.
We called pillbugs “rolly pollies” growing up. They aren’t insects: they are a type of land crustacean. One marine version is huge.
Because ladybugs are voracious, cannibalistic predators that scythe their way through the helpless like a nightmare from a 50’s movie.
They don’t bite, they don’t sting, they’re not poisonous and they look pretty.
That’s like asking “Why don’t most people kill butterflies?”
Yeah, there are other bugs who aren’t usually killed too. Butterflies, many types of moths, dragonflies (unless someone believes they’ll really sew their mouth shut)…pretty much any sort of insect they make jewelry to look like isn’t routinely squashed.
Wait, do people really go out of their way to kill bees? That’s a bug that can fight back if you miss them the first time!
Mmmm…cheap lobster!
I usually leave carnivorous insects alone since I figure they’re eating more obnoxious insects. This includes ladybugs.
But just the red ones. I kill the invasive orange ones who are pushing the native red ones out because fuck those guys.
We called them “friendly bugs” because they weren’t aggressive.
My parents were less than thrilled with our choice of playthings. We also played with horny toads (horned lizards) and ant lions.
They look cute and they’re pretty rare in my experience - I see maybe one a year. That doesn’t mean they can’t swarm - a friend of mine had a bad ladybug infestation.
Thank you! Yes, that’s it. There’s many in the parking lot at work: I will sometimes see someone step funny, and it was simply to avoid stepping on one.
And wasps. Hadn’t we already stablished that Some People Are Morons?
I was taught not to kill praying mantises, too. They kill pests, and besides, they have this kung-fu master vibe to them that I don’t want to mess with.
Oddly, I never even really thought of it as a superstition. It was just another in the set of “silly lies grown-ups tell little kids”, like “thunder’s just God moving his furniture”, and “eat up your crusts, it’ll make your hair curl”.
I think the crusts thing is a superstition too.
I was also told that rain was God emptying his chamberpot. Bleurgh.