[thedoc (OP)]

FARINC  asked the Naked Scientists:
   We live in a 3 story colonial home in Arlington, Virginia, a suburb of Washington, dc. and have lived in our home for 30 years.  last week we had a snow storm with about 2 feet of snow and it was very cold. we turned the heat higher than usual, about 76 degrees, to keep the chill out. we then experienced the strangest thing.  our home was infiltrated over the week with house flies, house flies of the gargantuan variety.  we've never had house flies to speak of in 30 years of living here, maybe one here or there sneaking in the door during the summer, that's it. anyway, it was so bad that i had to buy those sticky things that you unroll and hand from the ceiling. of course, those only work if the flies just happen to fly in to them as there's nothing to attract them to them.  I soon learned that they would fly towards light so at night i would go from room to room turning on a light to attract them, then turn on the light in the next room and then turning off the light in the last room. i did this until i got them to fly in a bathroom where i put up all these sticky hanging thingys.  by morning time, i would discover that most of the flies would have flown into the sticky things and get caught. other times i would herd them towards the mud room, shut the door and then open the mud room door to the garage, turn on the lights in the garage, and off in the mud room and they would fly in to the garage.  shut the door.  this went on for the entire week.  during the week our temperatures were above normal, in the 50s for the most part.  anyway, after a full week of battling these things, i counted killing about 60 plus with the sticky things and probably another 15-20 who dies by themselves in the windows and i personally killed upwards of 30 - 40 myself by smashing them with tissue paper when they were hanging out on the window seals.  so tell me, what the heck caused this to happen and where did they come from? From our attic? From the basement? This is the most bizarre thing we've ever seen. i'd really love an answer.


 
What do you think?