Humans tend to think of ourselves as separate to the rest of nature, somehow. It's a strange part of the human condition—it's why we think of ecosystems as things that exist in the wild, rather than as things that include us. It's the reason why we get funny about spiders coming into our homes, and it's why we may be pretty upset to learn that microscopic mites live on our faces and eat our skin.
There are more tiny bugs around than you realize—and some of them like to take up residence in, on, or around people. Some are completely harmless and can be washed away with soap and water, others are blood-suckers that will leave itchy, raised bites, and a select few can cause serious problems for their host. Here's a quick look at some of the most notable human parasites.