The shelf life on the original Terminate containing Sulflurimid was reportedly around 10 years. Since the Stakes are around 11 years old, they may or may not be any good. The new Terminate uses a different chemical called a "chitin inhibitor" that prevents termites from molting or shedding their body covering to grow. It is superior technology compared to Sulflurimid. If you decide to use the old stakes, just be aware that it takes about 2 years for them to work to full effect.