How Do Cockroaches Pick Up Speed So Quickly?
Anyone who has ever spotted a cockroach can likely attest to the fact that they are great at picking up speed and making an effective getaway from a rolled-up newspaper. So how do roaches manage to become so speedy when they need to? It turns out that roaches can actually change the way their legs move in order to pick up speed. Those who have spent time around horses know that horses use their legs differently when trotting as opposed to galloping. This is exactly what roaches do. Most insects likely have one setting at which their legs function. Roaches are special in this regard, as researchers have recently discovered. In fact, roaches are the first insects in history that have been found to change their own movements from a crawling mode to a running mode.
This discovery was made by Tom Weihmann of the Institute of Zoology at the University of Cologne in Germany. Weihmann and his colleagues used the roach species known as Nauphoeta cinerea to demonstrate this change in movement. The experiment started by first removing the roach’s wings so they could not fly. Then the roaches were placed on a fifty centimeter long racetrack. The researchers induced the roaches into movement by pushing them with puffs of air, or by tickling their legs with a paint brush. The researchers noted that the initial stages of movement involved a sort of leg movement known as the “tripodal gait”. This form of movement occurs when one set of legs shows two legs moving at the same time as one single leg on the other set. One side of a roach showed two legs making contact with the ground while the other side showed one leg making contact with the ground simultaneously. This form of movement is ideal for maintaining a relatively brisk speed while also retaining balance. However, at greater speeds, the tripodal gait can result in wobbling and an eventual loss of balance. The roaches avoided this loss of balance when accelerating by switching to a form of movement that is known as the “metachronal gait pattern”. This pattern involves the same legs on each side of a roach moving sequentially from front to back. This switch in movement allowed the roaches to move much faster while maintaining balance. Although roaches are currently the only insects that are known for “phase-shifting”, Weihmann believes that many other insects resort to the same styles of acceleration. This study may also help engineers to construct more balanced walking robots.
Have you ever witnessed another insect accelerate, as opposed to maintaining a constant speed?