The main differences between wasps and hornets are in their appearance, behavior, and nesting habits. Hornets are generally larger and have thicker bodies compared to most wasps, which are more slender and have a defined "waist."
Hornets are less aggressive than yellowjackets but will still vigorously defend their nests. Wasps are often more aggressive and can sting repeatedly if provoked.
Regarding diet, hornets typically hunt larger insects, while wasps feed on a mix of insects, nectar, and sugary substances. Nesting habits also vary: hornets usually build large, enclosed nests high off the ground, while Yellowjackets may nest in the ground or exposed areas.