I hate these movies but the whole circle of life thing is the best description of life and death that I can think of. At least what a 5 year old would understand. Recently catherine ( 5 as well ) asked me how she came out of me when she was a baby.
I feel for you, but I think you explained it perfectly to your kiddo. When he's older he'll get it. Its like watching bug bunny cartoons when you're 15 as compared to when you were 5. Its like a jack hammer to the forehead. Shrek's got nothing on bugs for adult innuendo.