The earworms you can't get out of your head

If you've ever had a song stuck in your head you'll know it's annoying. But as Dr Karl Kruszelnicki explains, it might be an evolutionary way of keeping us alert to attack or stay focused during repetitive tasks.
Read more: http://www.abc.net.au/radionational/programs/greatmomentsinscience/the-earworms-you-cant-get-out-of-your-head/8064664?source=Snapzu