Naked mole rats are rarely seen since they spend their lives underground but they are actually amazing creatures. For one, they live longer than other rodents. They are also resistant to cancer and to top it all off, they don’t feel pain. They can’t because they lack the neurotransmitter that tells the brain about pain. Scientists believe this is an adaptation which allows the naked mole rat to survive in an environment high in carbon dioxide, which can cause acid to build up on their skin.