This pest has strongly survival instinct. Although they lost their head, they still live for some weeks. The scientists discovered the reason why they can do that and the human cannot.

Physiologist and biochemist Joseph Kunkel from Amherst University, Massachusetts (American) has studied the development of cockroaches to find out the reason why they can live without head and the humans cannot do that.

Firstly, the loss of head can lead to bleed and blood pressure decrease in order that oxygen and nutrition cannot be transport to tissues in the bodies. “Human bleed to the death”. Kunnel commented.

In addition, human breath by mouth or nose and the brain control this function. Therefore, when the human lost their heads, the breathing will stop. Moreover, human cannot eat without head and certainly they will die because of starvation.

However, the cockroaches are not required to have blood pressure like human. “Different from human, they have no large blood vessel network – it means that the small vessels need a huge pressure for circulation. They have an open circulatory system with lower pressure.

“If you cut their heads, the necks will be closure by clots. There is no bleeding control” Kunnel said.