Lost Sippy Cups

You go to your car and notice a smell, you check the baby, clean pants, you check Sam sneaks, all good! You decide it must be something in the air. Next time you open the door you smell it again, you search for the smell...no bottles, sippy cups, rogue chicken nuggets, what could it be? Days later the missing sippy cups rolls out from its hiding place with milk that would probably be turned into cheese in France - YUCK! You found the smell but now you have to empty the cup and have the smell in your house (or just throw it away which I have done before). Smell solved, lunch ruined!