Why does mold not grow on honey?

Gluconic acid makes honey an acid medium with a low pH that is inhospitable to microbes such as bacteria, mold, and fungi, while hydrogen peroxide gives short-range protection against these same organisms when the honey is ripening or is diluted for larval food.
Honey bees also reduce the moisture content of nectar, which gives it a high osmotic pressure and protection against microbes.
(And that's the truth! )

http://www.beeculture.com/beeculture/months/97jul/97jul4.htm

Thanks so much Tex! And for the site to.