Yesterday I saw my first and second bald-faced hornets of the year but did not get a photo. They were queens looking for a good place to construct a nest. That might seem like something to discourage, possibly even grounds for extermination, but this is our only native hornet, so I tend to cheer for them.
Years of encounters with stinging insects have lead me to be comfortable around them. They will sting ruthlessly if you get near their nest, but outside that danger zone of a couple square yards, they will not sting unless provoked. Unfortunately, many people's reaction is just that: swat, flail and freak out. If human stupidity were met with painful stings more often, the world would be a better place. Perhaps it's a bit misanthropic, but I'm on the side of wasps and hornets and against stupidity.
This is the time of year when being diligent and observant pays off. Inspect your porches and outbuildings for nests now. Early morning is a good time for inspection since wasps fly poorly when they are cold. If you can find nascent nests before the founding queen has hatched her first brood of workers, extermination can be achieved with minimal risk to you or the insect. Once that first brood hatches, there is almost always a sentinel on guard. When it's just the founding queen, she'll be away from the nest often, and when she is, knock it down. When she returns and finds her work destroyed, she will most likely take up her mission elsewhere rather than rebuilding in a cursed location.
Why might you want wasps and hornets around? They are nature's janitors. They spend most of their time hunting for dead insects and animals, which they feed to their larvae. Despite their aggressiveness toward intruders, they are not predators, just opportunists. Adult wasps and hornets feed mostly on nectar, saving richer meals for their brood, so they work a little pollination duty into their routine.
If you are going to get stung by these social insects, it will likely be from wandering too close to a nest you did not know existed. Nests up in a tree or near the peak of your roof are not a danger. If feel safest when I know where the nests are, so I go on inspection runs now when it is easy to respond. Sometimes I choose to let the nest be, knowing I can avoid it. One year bald-faced hornets nested under the awning of a window that is painted shut. It was perfect. I could safely watch them from inside. One day I came home to find the nest in ruins. The summer tanagers, known locally as "bee birds," had found the hornets and made a meal of them.
You might want to keep them around as tanager food.