7. Tsetse flies

The tsetse fly lives in rural Africa, where it spreads sleeping sickness. There are less than 5,000 cases reported each year, but the death count is rather uncertain. Plus, it’s likely that more people get the disease than we know. Sleeping sickness can be cured, but some people just don’t have access to the cure.

The good news, though, is that there are fewer and fewer cases each year. In 1998, 40,000 people reported they had the disease, so in just a decade it’s prevalence has gone down drastically. But just in case, get your swatters ready for if you see this little fly.