I have an airplane. I've had it 4 years now, and every spring/summer I put it outside. Yesterday I noticed flies on it. I shooed them off. Today, flies are back on it but are dead. Upon closer inspection, the plant appears they have then wrapped up like it's eating them! Are/can they be a carnivorous plant?! I'm so intrigued and feel silly for asking! I've never heard of this plant eating bugs. Thank you for your time I'm anxiously waiting for a response and am willing to send pictures.
There are many types of flies and I can't say for sure what insects you are dealing with.
Other pests do eat flies and perhaps they have found your supply to dine on.