Flies

Flies have been part of The Sims series since the beginning. In The Sims, they would appear over plates of spoiled food, and would eventually appear over piles of trash, dead mice, and pet droppings. In addition, "free range" flies would often appear if the house or lot was messy -- even unmade beds could cause them to appear. These flies were not harmful, but would reduce a room's Room score. In Unleashed, dogs would sometimes jump and snap at "free range" files, but could not get rid of them. "Free range" flies could be picked up and sold in Buy or Build mode if the move_objects on cheat was enabled. Oddly, they would be labeled as the "SSRI Virtual Reality Set".

In The Sims 2, too many flies on a lot can result in Death by flies, in which a Sim is eaten alive by them.