I don't really hate any animal. Not really a fan of how small bugs are, though - It just makes them way too easy to kill by acident, and when your me, even killing an ant makes you feel like a dick.
I suppose my worst animal - I still don't hate them, but I like them about the least, which is still pretty much mind you and OH GOD RAMBLE RAMBLE - Would be a fake wasp. I forget the actual name for the bug in question, but calling it a fake wasp is about right - It looks like a wasp, but it doesn't have a stinger, and if I recall corectly, it doesn't fly either. That doesn't change the fact that it LOOKS like a wasp, and if you don't like pain, like me, one of the many things you want to stay away from is a wasp. So you stay away, hoping it flies off... But it doesn't. So you have to slooooowly crawl up to it, and sloooowly get it on a piece of paper or something, all the while thinking "Why isn't it stinging me allready?" And then, you start to think "Hey! I remember hearing about fake wasps..." And you start to feel just a tiny little bit of anger towards the bug in question. "Faking looking like a wasp? What a twat!"
... Eh, whatever. You probably don't see them much - They're hard to find even in england, an the USA is a LOT different in terms of climate, so they probably couldn't really thrive over there... Maybe they do. Who knows? Do I look like a bug expert?