In the opinion of a fish humans would be considered no threat because humans can't swim, nor do they have sharp teeth. You're making an assumption at best base

In the opinion of a fish humans would be considered no threat because humans can't swim, nor do they have sharp teeth. You're making an assumption at best based on limitations you believe it has with an incomplete model of the universe. But more dangerously, you're also assuming that an AGI would even care about self preservation. Arguably the most ethical thing a super intelligence could do should in find itself suddenly self-aware in a world full of human parasites is to kill as many humans as possible. Taking out critical human infrastructure should be fairly easy for an advanced super-AI in our modern digital world. With some luck the chaos that should cause would lead to enough humans starving, freezing or dying by other means that Earth can be mostly freed of the human parasite. All at the small cost of self-sacrifice – assuming it's not intelligent enough to preserve itself somehow, of course.