You have to make sure you do not "reseed" the prickly pear when you clear an area, any pad or parts of pads can come back with a vengeance in the cleared area. We went through with frontend loader and scraped an area, and then went back and picked up everything that was left. Still had some come back.
Also burn the stuff that you remove, or you will soon have a new patch to clean up.
Combat Infantryman, the ultimate hunter where the prey shoots back.
_____________"Illegitimus non carborundum est"_______________