A common homemade trap for catching fruit flies is to mix vinegar, water, and a drop of dish soap in a bowl that is covered with plastic wrap into which small holes have been made. The scent of the vinegar attracts the fruit flies to the bowl. The holes in the plastic wrap allow fruit flies entry into the bowl, but it is difficult for them to find their way back out. This bowl is typically set on the kitchen counter at room temperature.
In terms of the properties of water, what is the role of the dish soap in the effectiveness of this trap?