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Japan uses the same words for a lot of animals. Kuma/Guma, for example, means bear and badgers are called anaguma AKA "hole-bears" because of their tendency to dig. Nezumi, the word for rat, is the exact same case.
Hedgehogs? Hari-nezumi. Therefore, by technicality, a hedgehog can be considered a rat in Japan. Not sure about Bidoof though.