Cockroaches do exist and are among the creepiest creatures. These insects generally have a bad reputation because of their appearance, habits and tendency to live in unclean places.
Their ability to thrive in almost any environment, combined with their nocturnal habits and propensity for hiding, means that they tend to be more noticeable when they’re unwanted guests than when they’re just going about their business.
Also, their habit of eating anything that won’t bite back and then digesting it from the inside out is not exactly endearing! So why do cockroaches exist? Are they just another one of nature’s weird experiments or do they serve some purpose? And how did this particular species of cockroach get so numerous?
What Are Cockroaches?
Cockroaches are insects of the order Blattodea, in the same family as termites. There are around 4,000 species of cockroach and they are found in every continent except Antarctica. In the southern hemisphere, cockroaches are predominantly tropical species, whereas, in the northern hemisphere, temperate species predominate.
The different species vary in size from a few millimeters to over 50 centimeters long. Cockroaches are generally nocturnal and omnivorous, feeding on a wide variety of food sources such as decaying matter, fruits, vegetables, grains, live plants, leather, paper, book bindings, and even starch in book bindings.
They have mouth parts adapted for chewing and can eat material several times their size. Cockroaches can live for up to a month without food, but no water, and can survive on very low levels of air humidity.
Why do cockroaches exist?
The Blattodea are among the most successful groups of insects, and they seem to have been around for a long time. Fossilized cockroach wings have been dated to the Carboniferous period (between 354 and 323 million years ago) and molecular evidence suggests that the order originated in the late Palaeozoic (between 252 and 66 million years ago).
The Blattodea are thought to have evolved from a group of insects that were already living in trees, possibly as long as 165 million years ago. Although cockroaches are rarely mentioned in lists of the world’s most threatened species, there are several reasons why the group is worth considering.
After all, the world would be a very different place without cockroaches! In many ways, the Blattodea are the quintessential generalist species, capable of living in a wide range of environments, eating a wide range of foods and having a wide distribution.
It is also thought that some species are relatively long-lived and may be capable of replacing an individual after it has died after several years.
Such a long lifespan and the ability to replace an individual that has died is unusual in species with high reproductive rates; it is thought that these characteristics may be responsible for the success of the Blattodea as a whole.
Does cockroaches have a purpose?
For certain species of cockroach, humans make the perfect roommates. Why do cockroaches like living in our houses? And what do they do when they’re not bugging us?
Although most us think of cockroaches as vermin, they do have a useful ecological role. Cockroaches are professional recyclers, chowing down just about anything, including dead plants and animals, and animal waste.
Their digestive systems are up to the task because they contain bacteria and protozoa that help convert the world’s waste into easily-absorbed nutrients. In the wild, the waste of roaches nourishes growing plants, continuing the cycle.
Why Do We Have Cockroaches?
Even though they are generally considered pests, the Blattodea are thought to be extremely important in ecosystems around the world. As omnivores, cockroaches eat a wide variety of plant and animal matter, as well as many types of human food.
Cockroach droppings may also serve as fertilizer for plants. The ability of some species to live in a wide range of environments and their capacity to survive for long periods without food or water makes them exceptionally resilient, enabling them to survive in extreme conditions where other species would not be able to live.
These qualities may also explain why the Blattodea have managed to maintain such a high level of diversity despite the effects of climate change and habitat destruction.
Conclusion
The Blattodea is a very successful order of insects, with a wide distribution and a high diversity. They are thought to be important in ecosystems across the world, both as predators and as decomposers.
Although they are commonly considered pests, cockroaches may be important in the survival of human populations in the future, as they are capable of living in a wide range of conditions.