I worked at walmart in Wilmington, News Center one. We had ants penetrating the walls underneath the grocery racks where the stock is stored. They were coming in for the flour, cake mixes etc. that were stored on the lower shelves at knee hight. There were ants all in the food so we went through them and disposed of what we could see. My boss got RAID ant spray and went to town with it. Yes, folks all over and around where the stock is kept a toxic poison ant spray. I questioned his action and he knew that we were suppose to call in an exterminator to use food safe methods. Do you think he cared? The web worms are probably coming from the bags underneath the NEW ones on top. They do NOT rotate stock. The bottom ones are probably ancient.