They are attracted by food and garbage and even by attractive places to nest.
While many people are scared of wasps, some types of them are actually completely harmless.
Just in case you can not identify the wasps, here is how to tell what kind of wasps you are dealing with by looking at the kind of nests they've built.
Yellowjackets, baldfaced hornets, and paper wasps construct their nests from a kind of papery pulp.
Most yellowjacket and baldfaced hornet nests, furthermore, are constructed as a series of rounded combs.
These are typically stacked in tiers and covered over by envelope-type structures.
Paper wasps construct a single comb and they do not develop any protective envelope.
Their nests sometimes look like umbrellas, which is why they are sometimes called umbrella wasps.
They build nests under any horizontal surface, including around limbs, overhangs, eaves of buildings, attic beams, garages, barns, sheds, and the like.
Yellowjackets generally build nests below ground, although it is not unheard of for them to build nests in trees, in shrubs, under eaves, inside attics, or inside wall voids.
Baldfaced hornets typically build nests in the open in trees, under eaves, or along the sides of buildings.
Yellowjackets, baldfaced hornets, and paper wasps tend to build their nest in quiet places that are away from traffic areas.
They tend to pose the biggest problems in urban areas.
The key to just about every wasp problem is knowing what type of wasp you are dealing with and making an assessment about the proximity of their nest to your activities.
If you have a nest of yellowjackets under your kitchen window, the chances are you need to destroy the net and its inhabitants.
In a more ideal world, if you have a wasp nest in your back yard but at a distance from all traffic, you might decide to apply less dramatic techniques to keep your home pest-free.
Remember that many wasps are helpful to a garden, and so if you can find a way to life peacefully with your new neighbors, you might end up with better vegetables and flowers.
And, of course, just because you do get rid of a wasp nest, that does not mean the wasps are going to necessarily give up and go away.
If they like your property enough, they will just build another nest.
At least, maybe it will be in a part of the yard where you will mind less.