The Inuit ate not only the flesh of the seal but also the skin, which is rich in vitamins, and some of the blubber, an excellent source of energy. If there was enough, they also fed seal to their dogs. Most of the blubber was used as lamp fuel for heating and lighting their homes. Sealskin is light and strong and was therefore used for summer and spring clothing, boots, and kayak and tent coverings. The intestines were made into waterproof clothing and containers for water and oil. Sealskin becomes hard and stiff on drying, so the women had to chew on it to soften it. .