Why do mammoths not decompose?

Answer 1

Woolly mammoths were adapted to living in freezing conditions towards the northern most area of earth, for example where Siberia now is. As the conditions have remained freezing since the ice age, mammoths that have been buried under snow since they were dead have not decomposed. This is because as the stable freezing cold for millions of years slows down the animation of bacteria. They too are frozen in the process, and decomposition occurs because bacteria in the internal organs of the animal, and in the atmosphere multiply without the control of an immune system and devour the body leaving a soup like waste product. And of course flies, and other such life form that feed on carcasses are unable to get to it because it is buried deep in ice. This, combined with having the effect of bacteria eliminated from the remains leaves an almost perfectly preserved mummified mammoth.

Answer 2

Most mammoths did decompose. The ones that did not decompose were preserved because they remained frozen for all of the time after they died. This was because they lived in such a cold environment.