Reading the above comments, thought I'd write a few lines to help clarify the difference between borax and boric acid. Most of what the public uses borax for (at least in the USA) is purchased as a laundry detergent additive, the main product being "20 mule team borax", which is currently manufactured by Dial Corporation (yes, the Dial soap people). The main (active) ingredient in this product is sodium borate.
"Borax occurs naturally in evaporite deposits produced by the repeated evaporation of seasonal lakes. The most commercially important deposits are found in Turkey; Boron, California; and Searles Lake, California. Also, it has been found at many other locations in the Southwestern United States, the Atacama desert in Chile, and in Tibet and Romania. Borax can also be produced synthetically from other boron compounds." - from Wikipedia.
(They have a great article and detail the chemical properties of borax.) To get boric acid, one needs to add hydrocloric acid (HCl) to the sodium borate. The product "20 mule team borax" does NOT contain boric acid. But, as many have written and testified to, that the sodium borate does work well as an insecticide. Hope this helps some.
