The whole problem of "general" intelligence is that the "general" implies agency. If an AGI exists, it has agency, and it can do or not do things.
The humans with agency we have in the world are already enough of a problem. Let's not add superintelligent computers.
1) Ants did not give birth to our species.
2) We do try to solve diseases for other animals. If we could communicate with insects the way we do with other species, there would be an effort to help them. The biggest barrier is language, something that will not be the case with AGI.
And to be clear, I'm actually not an AI catastrophist. I just don't think any sufficiently advanced AI is going to be very motivated to help us with our puny problems. I think it's more likely they'll just fuck off somewhere far away where we can't bother them.