Have you tried wearing gloves? If there were roaches or rats in my room, I would like for them to be gone and find out the source and probably not leave food in my room.
I noticed I would leave a bag of trash in my room and I would get pests so I try to not have any type of trash, especially food trash in my room for longer than two days.
Maybe get yourself a bottle or a cup that has a lid for if you drink and set it down, you won't get any extra ingredients in your beverage.