Consider the location of the wasp. Paper wasps are typically found underneath eaves, in small plants and in other shady areas. Mexican wasps are found in bushes or small shrubs. Yellow jackets typically build nests in the ground, although they may have some aerial nests. Cicada killers live in gardens, flower beds and lawns.
Evaluate the size of the wasp. Paper wasps are approximately 3/4 inch to 1 inch long. Yellow jackets are about 1/2 inch long and cicada killers are considerably larger, measuring approximately 1 1/2 inches long. Mexican wasps are very small, with a length of 3/10 inch to 1/2 inch.
Examine the color of the wasp. Paper wasps have black wings that fold when they are at rest, with yellow or reddish brown markings. Yellow jackets are called yellow jackets because of their starkly yellow and black exterior. Cicada killers are rusty brown with yellow and black markings on their abdomen. Mexican wasps are predominantly black with a yellow tip on the end of their abdomen.
Observe the behavior of the wasp. Yellow jackets are known for their aggressive behavior. They can sting repeatedly without ceasing. Cicada killers typically are solitary and are not found in droves. The males make a loud buzzing noise but do not sting, while females can sting. Paper wasps often attack in groups when the nest is disturbed. Mexican honey wasps live in large swarms and fly very quickly. They often attack with little warning.