We consider ourselves to be the highest form of animal because:
1. We have yet to meet another animal that, by our standards, is equal to or “higher” than us.
The standards by which we judge this are entirely subjective, however, and are based more on survival and selfishness than anything else.
2. Is allows us to justify our actions, towards other animals, the planet, and to each other on the short term.
This style of thinking is outmoded, we would be better served to remember that we’re just another step in evolution – one that might be a dead end, and that other species are evolving as well.
As for being at the top of the food chain, there are still things that can eat us. And scientifically, the nice at the top of the food chain is now being occupied by various viruses and bacteria.