I seem to have a blue bottle infestation in my laundry room. All there is in there is a washing machine and tumble dryer. Ive had it all out, there's nothing dead in there. I just have no idea where they're coming from. I kill whats in there, and within a few hours, there's about another 20. I have no clue where they're coming from. What can I do, Im getting through cans of fly spray. I sick of clearing up dead flies.