[Avenger42]

The animal species that causes the most human suffering is... humans.

(Or were you being facetious? Especially since you shifted the argument from insects to animals.)

[ugh]

I would guess that’s why there is a “without any negative consequences” condition?

If I could, with the push of a button, kill any and all species which cause harm to humans without, in the process, causing harm to or even killing humans I would do it, too. Sure. No second thoughts about that.

[carbocation]

Insects are animals.