Sep 16, 2014 · If you think one spider is bad, try 2500 spiders crawling around your house. Hitchcock would have a field day with this idea. Female spiders nest and lay eggs under porches, in the moist soil of flower beds, under wet leaf piles, behind rotted wood, in the pocket of a cinder block, in the millions of nooks and crannies a ton of construction ... Sep 02, 2011 · My advice: in the room that their population is the most dense, go through anything that contains food such as cereal, flour, corn meal, seeds, nuts, pet food, grass seed, arrangements containing dried fruit, old hats/clothing in boxes, taxidermy mounts. Anything that contains naturally occurring materials, except cotton is suspect. Outside-breeding sites: House Flies may be found feeding and breeding in fresh manure, rotting fruits and vegetables, garbage, damp garbage, and decaying organic materials that are located outside of the structure. Most of the time, when you find house flies inside, it is because they are coming inside the structures.