Typically wasps tend to be more aggressive and will gravitate towards human food more so than bees.  Bees are seemingly more gentle in nature and are a lot more interested in flowers that your food.  If you find yourself stung your logical assumption can be that your attacker was a wasp.

This is just one, but quick and simple way to determine whether your sting was from a bee or a wasp. There other characteristics to define these two very similar creatures — both of which belong to the order Hymenoptera, a fancy word for the third largest order of insects.
Believe it or not, over 25,000 kinds of each insect exist, but there are several fairly simple ways to distinguish between bees and wasps.
If you are lucky enough to see the insect that stings you, take note of its physical characteristics.  Bees have hairy, robust bodies with flat rear legs while wasps are slender, appear to have a “waist”, are shiny and not hairy with slender legs that appear cylindrical in shape.

In the instance that you do not see the insect, you can inspect the site itself for more information.  Both bees and wasps inject a venom with a stinger that is attached to their bodies. Most wasps and bees can inject the stinger into your skin and remove it before flying away, except for the honey bee.  A honey bee’s stinger is barbed and it sticks to a human’s skin after being stung, therefore when a honey bee tries to fly away, it cannot do so without ripping the stinger from its body.  The stinger is attached to the honey bee’s digestive system and as a result the honey bee will eventually die from the experience.

For more information please go to the following site: http://www.emedicinehealth.com/bee_and_wasp_stings/article_em.htm

Photo Credits:

Kim Taylor/Dorling Kindersley/Getty Images (Bee)
Frank Greenaway/Dorling Kindersley/Getty Images (Wasp)