Make it illegal for pet shops to keep hamsters in cages less than 100x50x50cm, as stated as the minimum size by animal charities. Also ban companies from selling hamster cages that are too small. Stop individuals and companies from putting profit before animals' lives.
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It is inhumane keeping any animal in such a small space, without proper space to provide enrichment or to run around. These cages are too small for a proper sized wheel (28cm), therefore they are only big enough for a saucer wheel, which can cause curvature of their spines due to the way they have to run in them.