These fun wooden Smart Cubes from Duvo+ are the ideal toy for your rodent. They prevent boredom, encourage the natural gnawing instinct and keep its teeth healthy. Rodents' teeth grow all the time. They keep the growth of their teeth under control by their frequent gnawing. Made of quality wood, this makes a healthy and indispensable toy for your pet's cage. The letter and number blocks are coloured with animal-friendly dye and therefore 100% safe.