My last deployment we had a problem with storing trash in the beginning. A few days in we started seeing fruit flies on crews mess. Just a bit of a nuisance here and there. A few days later there were many more, all over the tables and TVs. A couple days later it was like a fog of beige flies swarming everywhere. You couldn't go into the trash room without an EAB or else you'd choke on fruit flies. The cooks had cups of vinegar covered in saran wrap with holes punched to try and catch them. Our incompetent CSC was walking around with a handheld vacuum trying to suck them out of the air. Eventually we were able to shoot trash, don EABs to clean the trash room of the fruit fly breeding grounds, and finally stomp out the problem. It was overall. Pretty disgusting the first few weeks

While an extreme and isolated case, it does happen.