How do house flies commonly feed?

House flies are known for their unique feeding method, which involves regurgitating digestive juices onto their food. This process allows them to liquefy solid substances, enabling them to ingest nutrients more easily. The house fly has a specialized mouthpart known as a proboscis, which is long and flexible, allowing it to access food sources, such as decaying organic matter or other substances they come across. When they land on food, they often expel digestive enzymes, which break down the food, and then they can suck up the resulting liquid. This feeding technique is particularly efficient for their diet, which consists of a wide array of organic materials.

In contrast, the other options present methods of feeding that do not align with the biology and behavior of house flies. Biting and sucking blood is characteristic of certain flies, like mosquitoes, but not house flies. Eating only solid food is too limiting for house flies, as they primarily consume liquids. Filtering tiny particles from the air does not relate to their feeding habits, as they rely on liquid nutrients rather than air filtration for sustenance. Hence, the method of regurgitating digestive juices underscores the distinctive way in which house flies obtain their nourishment.