Many folks wax nostalgic thinking of youthful days gone by. And while we are often looking back through rose-colored glasses and only seeing the good in those old days, some things really were better. For one thing, decades ago most of us in the Upper Midwest worried little about ticks, mosquitoes or black flies and their bites. If one attracted a tick, it was pulled off with little thought. Mosquitoes and flies were swatted, or we slathered ourselves with liquid DEET to repel the pests. But with exotic bugs and the diseases they carry marching north across our continent, we need to be aware of the risk they pose to health.