In addition to these simple homemade shelters, you can find nesting boxes sold in many petshops. There are small wooden houses that can last a fair amount of time with gerbils and other serious chewers. Theres also plastic houses that can be used for those that do not chew very much. Petshops also have items such as hallowed out fake logs, ceramic houses and round bamboo nests. Tubing is a great addition to any cage.
Tubes provide both shelter and amusement.
Tubes can be purchased in a variety of sizes, colours and shapes at petshops. Small hamster sized tubes can be used naturally for hamsters, as well as mice and baby rats. Mice love to run through these. Like the pet products they come in a variety of sizes and shapes- small ones suitable for mice and large ones suitable for rats. Provide your critters with some bird ladders, branches, rope toys or commercial drift wood and they will find hours of amusement with these objects each day.