Mystery Smell

I few days ago I started to smell a bad odor coming from the kitchen. I started to smell everything in the kitchen and couldn’t find the odor. I cleaned the garbage disposal and can, and I still can’t find the smell.
S thinks it might be one of the critters that we have been trying to get rid of might have gotten in the wall and died. But of course he made me feel better about that by saying, ‘The smell will go away at some point.’
This morning I didn’t smell the smell. The only thing I did was cut up a cantaloupe that we bought on Saturday. I can not imagine that it is the cantaloupe since I did smell that when I smelled everything and it smelled sweet and good. Could the smell get bad a distance away from the fruit?