It’s safe to say cockroaches don’t have the biggest fan base in the world. They’re almost universally reviled as disgusting, crawling initiators of psychological warfare. So it won’t come as any comfort to learn that they also have a “turbocharged” bite, one that is 50 times more powerful than the force exerted by their own body weight. The new findings have been published in the journal PLOS ONE.
The American cockroach (Periplaneta americana) is a jawed insect that's able to chomp down and chew on a variety of materials, from prey to almost anything they want to tunnel through. Classified as a pest, this creature can scurry around at a speed of 5.4 kilometers per hour (3.4 miles per hour), which would be the equivalent of a human running at 330 kilometers per hour (205 miles per hour).
The authors of the new study note that very little work has been done on the biting strength of insects, so to further our knowledge of the subject, they decided to focus on the "generalist feeding" American cockroach. To do this, they set up an extremely thin sensor that the bug could bite on with its entire jaw. This surface was highly sensitive to force and pressure, allowing the researchers to examine just how powerful the cockroach’s chomp was.
Image credit: An American cockroach bites down on a force sensor plate. Tom Weihmann
Using 10 specimens, the researchers enticed them to bite down onto the plate up to a total of 300 times. These tiny monsters were discovered to possess a bite that exerts 58 newtons per square centimeter (84 pound-force per square inch). For comparison, the average pressure of an adult male human bite is 103 newtons per square centimeter (150 pound-force per square inch), roughly twice as powerful as the cockroach’s.
However, a cockroach is roughly 43 times smaller than a human (by height), so relatively speaking, its bite is actually incredibly powerful. Taking this into account, the researchers note that the cockroach has a bite five times stronger than the average human. When encountering tough materials such as wood, they activate special muscle fibers to “boost” their bite, making quick work of your skirting boards.
“The weaker, shorter bites were generated by relatively fast muscle fibers, while the longer, stronger bites were driven by additional muscle fibers that take time to reach their maximum force,” said lead author Tom Weihmann, a zoologist from the University of Cambridge, in a statement.
The researchers note that it is currently unclear how their jaws withstand such powerful, repeated force over their lifetimes without experiencing significant wear and tear. Figuring out these mysteries could perhaps lead to advancements in miniaturized robotics and bioinspired engineering.
“Recent technical implementations in this direction are for instance micro-probes inserted into blood vessels or micro-surgical instruments,” Weihmann added.