I don't believe in any aliens even though I know it's possible that there's life on other planets. And if they are advanced enough to come here, then there's no way we will ever be able to detect them. Ghosts, nope. Bigfoot, or even primate anywhere natural in North America...instant Nobel so what's stopping you? Even among known things like mountain lions in rural California, why is it that people see them all the time but my ranger friends who are out there all the time have never seen one ever? I think this alone explains the bigfoot phenomenon.