Which type of fly is commonly referred to as "moth flies"?

The term "moth flies" is commonly used to refer to drain flies, which belong to the family Psychodidae. This nickname arises from their moth-like appearance characterized by their fuzzy, hairy bodies and wings that often rest tent-like over their bodies when at rest. In terms of their habitat, drain flies are typically found in areas with organic matter, especially in damp environments such as drains, sewers, and other places where standing water may collect.

Understanding the ecology and behavior of drain flies is important for effective pest management, particularly since they can be indicators of unsanitary conditions. Their lifecycle and breeding habits can influence how infestations are controlled, making it essential to identify them correctly. The other types of flies listed do not share this nickname or physical characteristics, which is why drain flies stand out as the correct answer in this question.