A Cozy Hangout • Provides an additional area to explore and enjoy • The clear plastic of the Den's roof makes it easy for you to see your hamster, while the retractable roof gives you easy access to your pet. • Your hamster may choose to use the Habitrail® OVO Den as a toilet or as a sleeping area. • If your hamster is using the Den as a toilet, ensure that it is cleaned more often. • You can add more than one Den to your Habitrail® OVO set-up giving your hamster both a sleeping area and a toilet. • Clean with warm water and mild detergent and rinse thoroughly.