Decomposition usually takes how many days?

My hamster died a few days ago and I found out today. My grandfather went to clean it and found maggots! I know when decomposition takes place, it will have maggots and give out a smelly smell. I knew this because I learn it since late July or during August. I wanted to know that what is the duration. I didn't feel really sad because it will help me for my science prelim exam tomorrow. Oh ya, I am using my mother's account so, you know. Thanks you if you answer this question.