The process of decay, or decomposition, for dead animals occurs in five stages: fresh, bloat, active decay, advanced decay, and dry remains. Depending on the availability of moisture and temperature, these conditions may progress slowly or rapidly. Fresh decomposition is the first stage, occuring when the heart ceases to beat and pump blood to all the cells in the body. This sets the stage through a vaiety of mortises, for the second stage, bloat, which is an accumulation of gases within the body due to microbial anaerobic processes. The third stage is concerned with blowflies and fresh flies laying eggs via oviposition within the body, and the maggots from those hatched eggs feeding on the liquids being produced from the microbes processing the soft tissues. Advanced decay results in the spill over of liquids away from the hard tissues (skeleton), usually leeching into the soil. I remember seeing where a deer had died in a vacant lot where the grass was not mowed regularly, so no one removed the carcass. There was a huge plume of grass in the springtime, marking the spot the deers carcass occupied. The final stage is dry remains, where nothing remains but the skeleton and perhaps some dried skin. This process is instrumental in returning used nutrients back into the soil and the atmosphere, fueling several cycles, such as the carbon and nitrogen cycle.