Mummies are the bodies of humans or animals in which some of the soft tissues (skin, muscles, or organs) did not decay after death. Some were buried with great care, but others became mummified because of natural conditions where they died. Mummification happens when bacteria and fungi cannot grow in the dead bodies.
In some situations, mummies might have fallen into a bog , which causes whatever falls into it to sink. The mummies that did fall into a bog, are called bog mummies. Mummies that did fall into a bog, have well preserved bodies. If you look closely at a bog mummy, you will see that it will still have hair, teeth, fingernails, toenails, and will still have the same clothes on that the mummy was wearing the last time it was alive.
Most mummies that were discovered ,were found in Egypt (some were located in bogs and some in pyramids.)
When Egyptians built the pyramids, they made them so difficult to get into. Some scientists were trying to get into a pyramid so that they could discover a mummy , and then got stuck in the pyramid. After about a couple days they died because they did not have any food and could not get out of the pyramid. The scientists got lost inside the pyramid.
Very often when mummies died, other Egyptians would put food and treasures inside the mummies coffin to bring good luck and happiness in the After Life.