Life in Wisconsin will not prepare you for Korean bugs. This little beauty ("little" meaning 2 inches across) was perched in a bush near downtown Chungju. His web was part of a larger network that spanned ten feet of bushes. The bushes were about three feet high, and maybe two feet wide, so we're talking 60 cubic feet of spidery goodness.
And this guy and his buddies were midgets. Don't believe me? Check out the Banana Spider, AKA the Golden Orb Spider. These darling little creatures are everywhere in Korea once the summer sets in. Dangling from trees (and into your face as you walk by underneath), hanging out in bushes (while you sit on the bench nearby), or just hiding under your bed. Their webs are strong enough that they've been known to catch birds. Everything I've read suggests that they are extremely reluctant to bite, and when they do, the reaction is about as bad as if you got stung by a bee. Not that I have any interest in trying that out.
And it's not just spiders. Mosquitoes are everywhere in Korea. Between the insane humidity, the monsoon, and the heat, the country is an ideal breeding ground for the beasts. They're about the size of a nickel, and can give you fun presents like malaria. Thankfully, that's only really likely if you're living near the DMZ. (For other health information about South Korea, check out the CDC's page)
There are even crazy rhino beetles, like this giant specimen for sale in a South Korean pet store. We haven't run into any of these yet, but it's probably just a matter of time. EDIT: Turns out, one of Erin's classes is keeping a nice, gigantic beetle as a pet. Here's a pick!
Lastly, of course, are the Korean Cicadas. These things are loud, as in 120 decibels loud. For comparison, that's like standing in the middle of a rock concert. They shriek all afternoon and well into the night, so sleeping in summer with the window open can sometimes be a bit... difficult.
So what I'm saying is, if you want to visit Korea in the summer, get some earplugs, mosquito repellant, and a flamethrower (for the beetles and the spiders) and you should be fine. Probably.
Maybe bring a few extra propellant tanks for the flamethrower, just in case.