Exterminator

Can someone please tell me why every classroom in the Russel Building has nats, and fruit flys in it? It's disgusting, and a distraction to learning. Fruit flys are known for being pests. They roam around old rotting fruit. Which means that these disgusting living things are infesting a rotten fruit somewhere in the building. Where is this precious fruit? I will personally someone five dollars to get rid of it.