They are the most worst law breakers ever. They invade, or try to at least, and we end up kicking their ass. Boom, their dead, and they regret ever coming here. And one thing that I always thought was they are illegal immigrants. They just come to Earth, always to Canada, and just assume they can live here crime free. Think about it, they might be among us, and if you find one and he tells you he's an alien, report him. You might get a cash reward. I'm just sayin'.