This doesn't truely answer the question, but parasites scare me. I can't really think of a warm blooded animal that strikes fear in me, but leeches & ticks certainly strike fear in me. I once waded into a muddy pond and emerged with my legs draped in leeches. To this day, the memory of of that day is palpable. Deer ticks are another phobia I have. For those of you who might live in arid climates, deer ticks are having a banner year. They spread lyme disease, which is a debilitating disease that saps one's strength and can cause joint pain. There's not really a satisfactory treatment for lyme disease. It simply has to work it's way out of one's system. Tape worms? Don't get me started...

"What evil lurks in the heart of men? The Shadow knows."
https://www.oldradioworld.com/media/...red%20Time.mp3

This blurb was the beginning of a very old radio show. As far as mankind is concerned, do you think some people are born evil, or is it a learned set of behaviors? Explain using examples.