Just disputing two things:

Firstly, several species of ants are known to make slaves of members of other colonies- same species or otherwise.

Secondly, Animals do not 'rely on instinct' exclusively, which is what I'm pretty sure you're going for here. Only the simplest of creatures act purely out of instinct. The general populace seems to have this idea in their collective heads that intelligence/sentience/sapience is binary- either you have it, or you don't. This is completely unsupported by any experimental evidence. Evidence in fact strongly suggests intelligence to be a continuum, with humans tending towards the upper end.

Moreover, humans are nowhere close to being 'free' from instinct. Instinct affects all of us, and our actual ability to override our own instincts is highly overstated.

Humans? Smarter than animals? Do you have any proof? ;)

we are the only animals that to my knowledge will hunt an animal to extinction

There are no snakes on the Hawaiian islands because the mongoose hunted them to extinction. When animals are put in a position of advantage, such as an invasive species with no natural predator, they will often kill off the organisms on which they live.

or knowingly destroy the planet on which we live

Algae create a massive dead zone in the gulf of mexico. Over-populated deer can destroy environments on which they thrive. Balance is only returned after years of starvation, or growing populations of predators thin out the heard and allow for the ecosystem to recover.

or invent "better", more imaginative ways of killing each other

Apes will beat each other with sticks. That's innovative. It may not be en mass, but if they were smarter it would be.

or hate another human just for their religious beliefs, sexuality or colour.

The apes that other apes choose to hit with sticks or rip their balls off are usually from a near by group that is viewed as a threat. That sounds like modern sociology to me.