Where did all those bugs come from?

When I called the Heating, Ventilation plus A/C supplier they told me it would be about a month before they could get to the house

When I turned on my oil furnace last fall, I ended up with what looked love a pressing cloud, plus it came flying out of my air vents. I wasn’t sure what it all was, until I saw there were wings in the cloud. I realized I had bugs flying through my house, plus they had hatched in my ductwork. I ran downstairs plus turned off the oil furnace, plus called first the exterminator plus then the Heating, Ventilation plus A/C supplier. I knew I had to have the bugs eliminated before I had the ductwork cleaned. It took more than two afternoons for the exterminator to show up. She said she would need to do more than one treatments to make sure they got all of the bugs. She did 1 treatment the day she showed up, plus she put some kind of fog into the air vents. I had to leave my house until the fog cleared. Two weeks later, she returned plus did the same thing again. Once again I had to leave the house for more than one afternoons. She told me to let him know if I saw anymore bugs after more than one weeks, however she felt it was safe to call the Heating, Ventilation plus A/C supplier plus make an appointment to have the ductwork cleaned. When I called the Heating, Ventilation plus A/C supplier they told me it would be about a month before they could get to the house. I set up a time plus date for when they could wash plus sanitize the ductwork. They also sent an Heating, Ventilation plus A/C company to the house to wash the oil furnace plus make sure everything was toiling well.

HVAC company