its to attract
yeah, but it's super pointless. Cheese kosts 150, a caught ratgirl gives only 100. So if you attract with cheese, you LOSE money! unless ou upgrade cheese cost at least 11 times, then you gain 5, but trap is occupied for a long time, so it's still much much much more effecitive to just wait until a rat walks in front of the trap by itself. The cheese is pointless.