3 astonishing facts that will make you appreciate cockroaches like never before
Science reveals their superpowers & how we can harness them
They spread like wildfire and transmit disease. They’re ugly, appallingly fast and surprisingly hard to kill. But here are three facts that will make you appreciate cockroaches like never before.
Now, I’m probably the last person in the world who should be writing this post. My friends, family, and unlucky passersby can tell you that my reaction to a cockroach sighting is anything but dignified. And then there was that awful time I had to do a lab activity with giant cockroaches in grad school… I still have nightmares about that.
But living in today’s cities, one must make peace with the fact that cockroaches will be a part of life. As one exterminator said to me, chuckling as he placed roach poison in my cupboard, “You live in a New York apartment. You’re going to see cockroaches from time to time.”
Indeed. So let’s look at the bright side, shall we?
1. They may provide us with new antibacterial drugs
Cockroaches live in cesspools infested with all sorts of bacteria, including “superbugs” which have developed resistance to many commonly used antibiotics. Have they evolved some way to protect themselves from infection? Researchers are now investigating chemicals found in different parts of the cockroach body to see whether they have antibacterial properties. Turns out there are some powerful antibiotics in the cockroach brain, only a few of which are similar to existing drugs. [1] By isolating and studying these compounds, we may be able to create new and more effective antibacterial medications.
2. Scientists have created remote-controlled cockroaches to use for good or evil
Sound like the stuff horror movies are made of? Well, believe it or not (and I never thought I would actually say this), the remote-controlled roaches are kind of cute, for a roach. (For the brave of heart, click here to see one: picture )
So how does it work? First, scientists implant electrodes in the cockroach’s prothoracic ganglia, which are big bundles of nervous system cells in the insect’s torso which control the muscles of the front legs. [2] In order to be able to send little pulses of electricity through the electrodes, the scientists also attach a small “backpack” to the roach’s back containing a microcontroller and a battery — after all, it would be awkward to have the roach trailing wires.
Starting to feel sorry for the cockroach? Fortunately, the process is fairly painless. The researchers first anesthetize the insect, and the whole operation only takes about 2 minutes. After that, the insect mainly feels the extra weight of the backpack. The prothoracic ganglion itself lacks sensory nerve endings, so the roach does not feel pain from having electrodes implanted in it.
As you have probably observed, cockroaches are almost always on the move. (This is why the scientific name of the large cockroach genus which includes the American cockroach is Periplaneta [3], meaning “wanderer”.) So as the cockroach walks, all the researcher has to do is push the left or right button on the remote control to activate either the left or right electrode, which will make the roach turn in the opposite direction. The method is not foolproof, for technical reasons and also because the cockroach has its own plans and can override the signal if it really, really wants to go in a different direction. But the remote control works about 60% of the time, and the scientists are working to make that number even higher. Want to see a video? Check it out: video
So other than being creepy and futuristic, what is the point of this technology? One goal is to equip such remote-controlled roaches with tiny cameras and send them into otherwise inaccessible spaces, like the rubble of collapsed buildings after an earthquake. The roaches can be directed to search for trapped people and animals.
Of course, one could also use such camera-equipped insects for spying. Like any new technology, we must use its power wisely.
3. If you cut off a cockroach’s leg, it can grow back
The history of this discovery is very interesting. In the late 19th century, British biologist H.H. Brindley was studying individual variation in insects. He observed that cockroaches typically have 5 joints in each “foot”, but many cockroaches would randomly have one or two feet with only 4 joints (they’ve got 6 legs all together) [4]. As it turns out, the 4-jointed feet are found on regrown legs, while the 5-jointed ones are on the original legs. So the next time you kill a cockroach, (if you have the stomach for it), bring out your magnifying glass and take a look at its feet. You might just learn something about the roach’s life story.
In fact, cockroach legs have a built-in weakness at two joints (roughly the roach equivalent of the hip and ankle), so that if a leg is trapped, they can save themselves by sacrificing the leg. Roaches can actually continue to live, move, eat, and breed with one or even two legs missing. Not only that, but in about 5 weeks, a new leg will start to appear in place of the missing one. [5] Full leg regrowth takes about 3–5 months. And if you were one of those disturbing children who tortured cockroaches by cutting off their legs, you can be somewhat comforted by knowing that those legs also probably grew back, although it would have taken about twice as long [5].
Of course, we humans wish we could mimic the roach’s ability to regenerate lost limbs. Researchers are studying the molecular mechanisms involved in this process [6], so that perhaps one day, we too will be able to regrow injured arms and legs.
So what did I tell you? Cockroaches are pretty amazing! And to make sure you don’t have nightmares tonight, let’s end on a positive note by looking at some gratuitous pictures of cute animals.
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Sources
[1] Ali, S.M. et al. (2016). Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana). Applied Microbiology and Biotechnology Oct 14(Epub). doi: 10.1007/s00253–016–7872–2
[2] Sanchez, C.J. et al. (2015). Locomotion control of hybrid cockroach robots. Journal of the Royal Society Interface 12: 20141363. dx.doi.org/10.1098/rsif.2014.1363
[3] Myers, P. et al. (2016). The Animal Diversity Web: Periplaneta. Retrieved from http://animaldiversity.org/accounts/Periplaneta/classification/
[4] Brindley, H.H. (1897). On the regeneration of the legs in the Blattidae. Proceedings of the general meetings for scientific business of the Zoological Society of London, 903–916.
[5] Marzullo, T.C. (2016). Leg Regrowth in Blaberus discoidalis (discoid cockroach) following limb autotomy versus limb severance and relevance to neurophysiology experiments. PLoS ONE 11(1): e0146778. doi:10.1371/journal.pone.0146778
[6] Farah, Z. et al. (2016). A concise review of common animal models for the study of limb regeneration. Organogenesis 12(3): 109–118
