The past couple days KLa has been waking up with a handful of bug bites. Worried that the mice we recently fought may have brought fleas into the house, she sprinkled Borax all over the floor before she left for Utah and drafted me to vacuum it up later that night.
As I was vacuuming it up, the thought occurred to me that it might not matter what powder you sprinkled on the floor. It could be glitter and be just as effective--what it did was show me how terrible of a vacuumer I normally was. It took me three or four slow passes to get up all the Borax and since my usual technique is one or two quick swipes, it's not hard to do the math and realize that maybe my standard vacuuming is fairly ineffective.
In short, regardless of whether the Borax actually did anything to the potential fleas, at the least it made me vacuum properly.