Typically, Shatter which is made of highly compressed cellulose, will last many months. In the soil. These cartridges are not applied until termites are active. Normally termites empty them within that period of time. When empty, it is best to replace the cartridge until the termites stop feeding. Here is a link to the directions - https://www.epestcontrol.com/images/Products/labels/shatter-termite-bait-label.