The main active ingredient in Fresh Cab rodent repellent is balsam fir needle oil, a natural insecticide and pest repellent. Fresh cab also includes a large number of inactive ingredients, including corn husks, lavender, sage and citrus. Fresh Cab works because mice and other small rodents dislike the way that balsam fir needle oil smells, making them avoid areas treated with the product.
One of the main advantages of Fresh Cab and other botanical rodent repellent products is their non-toxic ingredients. Because Fresh Cab does not contain chemicals such as strychnine, warfarin or other poisons, the product is safe to use in areas frequented by pets or small children. Rodent repellents also eliminate the unpleasant odors associated with using poison.
Fresh Cab is most effective in small, enclosed areas. In larger areas, the product's fragrance becomes too dispersed to effectively repel mice and rats. To treat larger areas, the manufacturer recommends placing one Fresh Cab packet per each 125 square foot area. If this is not effective at driving rodents away, the manufacturer suggests adding additional pouches until rodents no longer appear.
Fresh Cab's manufacturer, Nixalite, asserts that its product lasts as much as three times as long as its competitors, with a maximum effective life of 100 days. However, for serous or chronic infestations, Nixalite recommends changing Fresh Cab packets every 30 days.