Depending on a variety of conditions, the rate at which dead mice decompose varies. The temperature of the surrounding environment is a significant factor in determining how rapidly a mouse decomposes. The size of the mouse also has an effect, with larger mice taking longer to decompose on average.
Frequently, the rate of mouse decomposition ranges from one to two weeks at the temperatures typically observed in human-occupied spaces. If the environment in which a mouse died is warmer, the rate of decomposition accelerates. The odour associated with the decomposing mouse remains until decomposition is complete.