These are a VERY handy addition, as sometimes rodent can die in areas that are inaccessible and the smell can be very off putting. Place one of these bags as close to where the smell is coming from and it will help absorb the smell. Odour remover bags are easy to use and last an average of 3-4 months in use and contain no chemicals, toxins or fragrances. Simply place the bag near the odour and in 24 hours the odour will be gone. The Odour bags do not simply mask odours, it removes them from the air