There is some controversy about the best type of bedding and nesting type material to use for small pets. It should not cause harm if ingested and should be free of dyes, perfumes and other chemicals. Generally speaking the bedding material (sometimes called the substrate) should form a layer over the base of the cage and absorb liquids. Undyed paper, soft hay and hardwood chips or shavings (usually beech) are all acceptable. Softwood can give off vapours which irritate the nasal chambers of small pets and should be avoided. A combination of different materials can be used. Many animals also like to make a nest to sleep in, particularly hamsters. For this they like to use soft, fluffy material but this is where the controversy heats up. VioVet no longer sell fluffy bedding material made of fine woollen or other fibres. Although it works fine for many hamsters and they love it, some swallow it and suffer serious digestive problems and occasionally death as a result. Others can get the fibres wrapped around their feet cutting off the blood supply and causing serious injury. The best nesting material is soft paper based. This cannot entwine the feet and will cause no trouble if swallowed. It is even acceptable to tear up strips of toilet or kitchen tissue and use these. If they are chewed and swallowed, they will not cause injury. Hamsters and many other animals will love to tear up the paper and construct their own special nest.