Licking is a natural behavior in dogs whether they are grooming themselves or trying to get to something they consider tasty. Some dogs habitually lick something like the carpet. Check and see if there's food that's been dropped. Some dogs will lick their front legs causing lick granulomas to form. Often dogs lick because they are bored and seek attention or stressed out. As long as you don't use anything on the carpet that can be toxic to your dog, it won't hurt her. Try exercising your dog more. Vary the route on walks to hold her interest. When you have to go out, leave toys with treats in them around the house to keep her occupied. Distract her from licking the carpet with an activity you can both enjoy. If you feel her licking the carpet is excessive, I would recommend a checkup at the vet's to make sure it's not health-related. You can also consult with an animal behaviorist. Never punish your dog for unwanted behavior as it will only increase stress and make her fearful of you .