To provide a method for breeding small animals by children hygienically and more simply on a mat in a case.

Small animals, for example, beetles (colepteron), stage beetles, Suzumushi (a kind of cricket), hamsters, prairie dogs, tortoises and the like are bred on a Bamboo powder as a mat in an animal breeding case without feeling the odor of their excretion. The bamboo powder is rich in protein, saccharides, minerals, and the like, in addition it has high moisture-retaining power and so nutrients and water can be readily fed to these small animals.