He worked for several upstate New York honey producers in the 1920s. In 1928 he moved to Vermont, and in 1931 he began Champlain Valley Apiaries. His beekeeping and honey producing business became one of New England’s largest, and included more than 1,000 colonies. In 1932 he discovered that carbolic acid fumes caused bees to take cover at the bottom of hives. This procedure enabled a single beekeeper to harvest more honey at once, making commercial beekeeping more profitable. He also developed bees that were more disease resistant and able to survive lower temperatures, enabling beekeeping in colder climates, including northeastern states such as Vermont. Mraz’s bees were the first producers of light clover honey, which is now recognized as the industry standard for light honeys. After allowing his bees to sting him in an effort to relieve his arthritic knees, he became convinced that bee venom could treat multiple sclerosis, rheumatism and other diseases by triggering an anti-inflammatory reaction, and became an experimenter in the field of apitherapy. Mraz was the author of 1995’s “Health and the Honeybee”. He also lectured internationally, was the author of numerous magazine articles, and was a founder of the American Apitherapy Society. Bee sting therapy continue to be practiced by adherents and is the subject of several long term studies designed to measure its effectiveness.