[Danny]

Even 4 weeks is a little too long for a chicken to live without its head. Try 4 days.

I'm not just saying that because it sounds silly, either. There is a practical reason for my dubiousness: Without a head, the chicken would be unable to eat, and would therefore starve before too long, even if it does not die of blood loss or lack of a brain. I believe what we are labouring under here is an Urban Myth.

Cockroaches, on the other hand, have been known to live for several months without a head. If properly cared for, they will continue to function until they die of starvation. In fact, it has been proven that Cockroaches actually show more signs of intelligence after decapitation than before: headless cockroaches learn about 60% faster to avoid getting electric shocks from live wires...