The cells (alveoli) filled with honey, pollen, and brood are made from a natural wax produced by the wax glands of bees. A complex product of a lipid nature, this wax contains several hundred compounds, including esters of fatty acids and alcohols (70%), free acids (14%), hydrocarbons (12%), free alcohols (1.2%), lactones (0.5%), water and pigments from pollen, propolis or brood (2.3%). Chemically very stable, this water-insoluble wax is perfectly resistant to hydrolysis and natural oxidation as well as to the acids and digestive juices of animals except those of wax moth larvae.