Xerxys

Well, that just means the house is old and was infested with insects. You need to fumigate, have it checked for termites and ants and see what happens from there. Many black widow species are immune to the fumigation poison used.

Check the house, all of it, for nooks and crannies and have them caulked (pronounced cocked, **giggles**) especially around the kitchen where you have roaches and rodents. Case in point, once all the house is purged of all insects, then the black widow spiders will leave.

An alternative. Get a pro to do the fumigation. They will bring poison you can't buy without a permit and kill everything alive in your house. This is probably best because it appears that not only is there more than one nest in your house but they have an established breeding and feeding ground zero.