Because of their size (and perhaps also due to jealousy of their cuteness), there are a lot of things out to get mice, including the internet’s favorite mouse-slaying terror, the common house cat. But because of their adaptability and speed, they are still one of the most wide-spread and successful mammal species on Earth – they can be found in almost any environment and on almost every continent.
Mice certainly are cute and harmless in their natural environments, but they can be devastating pests when introduced to new environments. In parts of New Zealand and Australia, the absence of natural predators allows them to breed unchecked and devastate local crops and bird populations. Many birds were able to nest safely in the South Pacific islands until mice were introduced there by European explorers.