Apache Paper Wasp Polistes apachus

Don't mess with these aggressive wasps during harvest season—they pack painful stings and a chip on their shoulder. Found throughout western North America, they're famous (or infamous) for building papery nests that dangle from buildings, eaves, and orchard trees. Farm workers in California's fig orchards know them well; they become extra cranky during harvest time in September and October.

Unlike honeybees, these wasps are solitary queens with smaller colonies, making them territorial and quick to defend. They'll nest almost anywhere—orchards, vineyards, houses—which explains why backyard encounters aren't uncommon. If you find one building near your home, admire from a distance and give them space to hunt.