https://www.nhm.ac.uk/discover/what-is-a-dumbo-octopus.html

Building a technological civilization underwater would be quite a challenge though!

Octopi is correct, in that it is an english language plural for octopus. It is not etymologically sound, certainly, as it's a latinate plural on a greek root.

So anyone telling you that any other form is wrong and insuating that 'octopi' is more correct is certainly asking to be mocked. But as we don't really do '-podes' in english, and "Octopusses" is a bit of a mouthful, I think we can accept any and all as more or less equally cromulent.

"Octopuses" is both understandable and correct etymologically since "octopus" is a normal English word.

Personally I'll use octopuses, just because I once confused octopi as a word for another species of the family octopodes belong to. Now I know it's a common plural, but it didn't sound like a plural to me back then.

I'd prefer to use octopodes, but I feel like this can too be confused with another species, and I don't want to sound all smart in saying it's actually a plural. Octopuses bypasses all that confusion, and probably everyone will understand that it's the plural of octopus, albeit some might have doubts whether it's the correct form or not.

The Romans conquered the Greeks militarily, but the Greeks conquered the Romans culturally. Saying "octopi" indirectly attempts to not acknowledge that.

https://ipa-reader.com/?text=%C9%92kˈt%C9%92p%C9%99di%CB%90z

and

https://ipa-reader.com/?text=%C9%92kˈt%C9%99%CA%8Ap%C9%99di%...

Not really. Ants analyze their environment and make decisions. They have some sort of psychological internal processes too - they can clearly experience stress and mental illness.

(AFAIK if you keep ants as pets mental illness is realistically the only way to mistreat them. Everything else they can handle on their own if you provide a source of food and water.)