Read this article and learn how to avoid swelling and prevent pain in case a bee, wasp or hornet has stung you.
Take an aspirin pill, slightly moisten it with water and place it on the place where the sting is. Hold the pill on that area for several minutes and then remove it.
The sting will not be visible, itching will disappear and you will not have any swelling, which in other cases can last even for several days.
This is an efficient and verifiable method.