Ziwei has thorns.

Some people think that the trunk of Lagerstroemia indica contains a special substance, similar to human sensory nerves, which can sense external stimuli and react. When the reaction quickly reaches the treetops, the branches will shake. Some people think that Lagerstroemia indica has a large crown, but its trunk is slender, "top-heavy", its center of gravity is unstable and easy to shake, so it will tremble when touched slightly;

Some people think that the wood of Lagerstroemia indica is special and has strong conductivity. When we scratch its branches with our fingers, the vibration caused by friction can easily be transmitted to other parts, thus causing the branches to swing. Others believe that it is due to the bioelectricity of plants themselves; Others think that crape myrtle is smooth and its branches are soft, so it will shake when touched slightly. Although there is no final conclusion, I believe that one day scientists will reveal the real reason why Wei Zi is "ticklish".