K.M.
It sounds maybe like they are attracted to something in your laundry detergent (especially since they are attracted to the shoes - perhaps from what ever is transferred from the socks after being laundered). I know where you can get phenomenal chemical and toxin-free laundry products with a money back guarantee. They contain the oil that is referred to in the information below. Chemical cleaners do much to undermine our health and environment. There are alternatives to commercial brand home chemical cleaners. They can be made with baking soda and white vinegar and tea tree oil. Please contact me and I would love to share the details with you. Otherwise, maybe this info may be a temporary quick fix in the meantime.
During my search to help I found this piece of information from someone who said: "Last year we had an infestion of ants in the kitchen around the sink and stove, and I keep a clean house too. I tried everything, ant baits only made it worse, it was like I had put out a picnic and rang the dinner bell. Any way I saw an infomerical for that guy who does the Pest Free Home books, and he said sprinkle cinnamon where they are coming in, so we decided to try it. My DH found where they were coming in at, which was behing the stove along the wall. We put cinnamon down and it worked like a charm, haven't seen an ant since. That will be all I use from now on. No harsh pestiside or chemicals and its smells good. Can't beat that! ; ) Hope that helps."
Also:
You may hear people mention Borax powder, but this is harmful if ingested (thus by using it you are sure to be inhaling it) and should be keep away to children and pets and will keep away most insects except ants.