I don't think it's necessarily "Okay" to kill anything, Jeri...if you don't have to or you don't have a darned good reason to. (smile) And I harbour no hostility against carpenter ants. They're very interesting little creatures. But I do have a practical concern here...which is that carpenter ants who are living in my house will inevitably destroy the strength of various wooden structures upon which my house depends...given enough time...and will damage the value and integrity of the house in so doing.    Therefore, it would be best (from my point of view) to remove them from the house. Since I have no practical way of doing that except to kill them...it becomes a question of balancing one thing (my desire not to hurt them) against another thing (my desire not to have them hurt my house). It's a question of establishing priorities. My house has to take priority in this case. It weighs larger in the scheme of things (for me) than the ants do.

I do my utmost not to hurt anything that can be simply removed in a nonharmful manner if it's causing some problem.

Similarly, ants will attack anyone who invades or damages their nest...to the best of their ability. They're defending their house. I'm defending mine.

You are quite right as to way rats got a bad reputation. However, it's still quite possible that another (hypothetical) society might have decided, for completely arbitrary cultural reasons of their own, to venerate rats, keep them as pets, worship them, train them to be circus performers or any other darned thing under the sun.

That's what people are like. They make up a set of ironclad beliefs and customs for ideas that seem like good ideas to them at the time. The next generation repeats those beliefs automatically. After a few generations no one (except a few philosophical types like me...and a few teenage rebels, probably) even thinks to question those beliefs.

And that's why we might all be keeping cute little rats as pets and exterminating wild cats and dogs right now... ;-)

And someone would say to you, "Cats and dogs have been known to spread disease, damage property, kill pet rats, and even kill human babies!!!" Horrifying creatures! They MUST be destroyed on sight!

That's how human culture works. It arbitrarily praises one set of things and arbitrarily damns another. It gets all dramatic about it too, because everyone loves a good drama, right? ;-D