Is the decay of animal wastes an endothermic or exothermic reaction?
The decay of animal waste is an exothermic reaction, as it gives off heat throughout the process. This is going to be more of a biology-related answer, but there are tiny organisms, such as bacteria, that break down the waste and use it for energy and, in the process, give off the heat you would feel if you were to touch it. An easy way to observe this without actually touching animal waste is to touch a compost pile as the plant matter decays – the process is essentially the same. If the reaction were endothermic, then the waste (or compost pile) would feel cold rather than warm, as the waste would draw in heat from the surroundings, creating the cold sensation.