Wire should be powder coated or stainless steel. Galvanised wire can poison a rat. Wooden cages may smell and rats may chew this type of cage. Plastic and glass cages have poor ventilation. Aquariums should have a wire top for ventilation.
Poor ventilation can lead to respiratory illness.
More Housing Information Bedding Rats should have litter available on the bottom of the cage to absorb smells from urine. Paper based litter is recommended. Pine, wooden shavings and clay may irritate the lungs and encourage respiratory disease. Pine oils may damage the liver. Rats enjoy nesting boxes - these can be simply old tissue boxes or plastic houses available from a petshop.