Dr Chris Smith and Relebogile Mabotja explore why it's hard to reach a human in customer service. How did humans migrate from Africa, and can we trace our ancient paths? Why do people and animals have different neck sizes? Can you really hear your heartbeat when your head's on the pillow? Why is swimming in cold water easier than taking a cold shower? Why do your ears block when you yawn or blow your nose? Why don't you notice yourself growing? Like this podcast? Please help us by supporting the Naked Scientists