Why do many organisms store fats rather than carbohydrates in their bodies?

I read this information from PRE-U TEXT STPM BILOLOGY,why do many organisms store fats rather than carbohydrates in their bodies? It is because fat contains more carbon-hydrogen bonds. They therefore have less than half the mass of carbohydrates for a similar quantity of energy stored. This helps to reduce body weight to make movement easier from place to place. Fats are insoluble in water and do not diffuse out of their place of storage. They also protect the body and internal organs, acts as heat insulator and waterproofing. Oxidation of fats produces metabolic water which can be used by some animals example desert animals.