Cockroaches: The Ultimate Survivors: Photos
Cockroaches survived the mass extinction that wiped out the dinosaurs, and they're adapting to resist our efforts to eradicate them.
Cockroaches are ancient insects that have been around for some 300 million years, and one of the reasons they've been able to stick around that long is that they're able to change with the times. These insects survived the mass extinction that wiped out the dinosaurs, and now they're adapting to resist our efforts to eradicate them.
Although cockroaches are known to eat just about anything, some roaches have adapted to sugar traps used by humans to kill them in our homes. To these roaches, glucose tastes bitter instead of sweet. Researchers from North Carolina State University conducted two experiments, one in which they gave the cockroaches two food options -- jam and peanut butter -- and another in which they directly analyzed the cockroaches' taste receptors.
This adaptation is just one example of this humble creatures ability to do what it takes to survive. In this slideshow, find out why the cockroach is able to endure just about anything.
Cockroaches are omnivores, so unless they have good reason for not eating something -- for example, because humans are trying to poison them with sugar traps -- they'll consume whatever they can. They even will eat glue, soap or leather to survive.
This ability is what allows the insects to fill so many niches, and be particularly suited to exist around people.
Cockroaches are not only flexible in the contents of their meals, but also the timing of when they are able to eat. Some roaches can last more than a month without food and over a week without water.
Perhaps most well known is that cockroaches can survive a week without its head. If a cockroach loses its head and later dies as a result, it will typically succumb to dehydration.
Beyond durability, cockroaches are built to play defense. They have an exoskeleton to protect their soft bodies, and will hide whenever they're in the process of molting their exoskeleton. The exoskeleton is not only rigid but flexible to allow the roach to crawl into tiny crevices.
Their legs are built for running. A human running as quickly as some cockroach species at top speed would need to travel 200 miles per hour to cover the same amount of distance in proportion to their body size, according to HowStuffWorks.com's Tracy Wilson. And if a roach loses a limb, some species can regrow them as they molt.
Anyone who has seen a large cockroach infestation might believe that the typical city block with a roach problem may hold hundreds of different species.
In fact, less than 1 percent of the more than 4,000 roach species pose a problem for humans. Cockroach infestations in most parts of the world are due to one species: the German cockroach.
All this diversity means that among cockroaches are a range of adaptations to fill specific niches around the globe, such as this one-of-a-kind glowing cockroach that once lived near the Tungurahua volcano.
How roaches reproduce varies from species to species. In most cases, roaches are oviparous, or they lay eggs within which their young develop outside the mother's body. In other species, eggs develop inside a mother's body. And one species, the Madagascar hissing cockroach, females give live birth.
No matter how cockroaches produce future generations, one thing they nearly all have in common is that they're able to produce swarms of new roaches in a short time.
Most cockroaches are night owls. They do their foraging and feeding at night and avoid the light. This allows them to avoid potential predators and competitors.
According to a study in 2007 by Vanderbilt University biologists and published in the Proceedings of the National Academy of Sciences, cockroaches are also better able to learn at night, and have a seemingly total inability to pick up anything new during the daylight hours.
If humankind were to come to an end as a result of a massive global nuclear war, cockroaches could plausibly survive the aftermath.
Although a cockroach within the blast radius of any nuclear explosion would be incinerated just like anything else, roaches would be better able to cope with the fallout as they are able to tolerate much higher levels of radiation than humans.
Cockroaches have a greater tolerance for radiation exposure due to cycles of the roach's shedding its skin. When cells divide, they are at their most vulnerable to radiation. While human have cells that are dividing constantly, roaches molt about once a week at most, which makes radiation's window of opportunity to attack cells much narrower, as noted in Discovery's Mythbusters database.
The cockroach's ability to withstand radiation isn't unique in the insect world or even all that impressive by those standards. Others, such as fruit flies or Habrobracun wasps, can endure much higher levels of radiation.