Health-wise, pests can carry diseases with them that humans do not want. Way back when, rats carried the bubonic plague with them, effectively wiping out millions of people in Europe. It’s kind of amazing to think a bug bite could kill you, right? But in some cases, that’s true. If anything, bug bites can cause horrible itching, as well as rashes and sickness. In general, people hate bugs, and can you blame them?