Some wasps tend to be more aggressive than others, though: Paper wasps, yellowjackets, and bald-faced hornets pose more serious stinging hazards while mud-daubers aren’t as aggressive.

Probably not. Some wasps, such as yellowjackets, don’t even build nests that resemble the decoys. While these devices do look like a bald-faced hornet’s nest, “I’ve never seen a study ...