Stealth behavior allows cockroaches to seemingly vanish (w/ Video)

Jun 06, 2012
This is an American cockroach under a ledge. Credit: Jean-Michel Mongeau and Pauline Jennings. Courtesy of PolyPEDAL Lab UC Berkeley.

New cockroach behavior discovered by University of California, Berkeley, biologists secures the insect's reputation as one of nature's top escape artists, able to skitter away and disappear from sight before any human can swat it.

In addition to its lightning speed, quick maneuvers and ability to squeeze through the tiniest cracks, the also can flip under a ledge and disappear in the blink of an eye, the researchers found. It does this by grabbing the edge with grappling hook-like claws on its back legs and swinging like a pendulum 180 degrees to land firmly underneath, upside down.

Always eager to mimic in robots, the researchers teamed up with UC Berkeley robotics experts to recreate the behavior in a six-legged robot by adding Velcro strips.

The UC Berkeley team published the results of the study on Wednesday, June 6, in the online, open-access journal .

Image (c) PLoS ONE 2012

Graduate student Jean-Michel Mongeau of UC Berkeley's biophysics group said he and his colleagues first noticed the roaches' newly-identified behavior while studying how they use their antennae to sense and cross gaps.

"As we made the gap wider, they would end up on the underside of the ramp," Mongeau said. "To the naked eye, it wasn't clear what was happening, but when we filmed them with a and slowed it down, we were amazed to see that it was the cockroach's grabbing the surface that allowed it to swing around under the ledge."

This video is not supported by your browser at this time.
A top view of a cockroach, P. americana, performing a high-speed inversion while running up a ramp. The first sequences are real time. The second sequences are slowed 10X.

"Cockroaches continue to surprise us," said Robert Full, a professor of who 15 years ago discovered that when cockroaches run rapidly, they rear up on their two hind legs like bipedal humans. "They have fast relay systems that allow them to dart away quickly in response to light or motion at speeds up to 50 body lengths per second, which is equivalent to a couple hundred miles per hour, if you scale up to the size of humans. This makes them incredibly good at escaping predators."

Surprisingly, the researchers discovered a similar behavior in lizards, animals that have hook-like toenails, and also documented geckos using this escape technique in the jungle at the Wildlife Reserves near Singapore.

"This behavior is probably pretty widespread, because it is an effective way to quickly move out of sight for small animals," Full said.

Image (c) PLoS ONE 2012.

Full's group then teamed up with the robotics group led by Ron Fearing, UC Berkeley professor of electrical engineering and computer science. In Fearing' s lab, graduate student researchers Paul Birkmeyer and Aaron Hoover attached Velcro to the rear legs of a small, cockroach-inspired, six-legged robot called DASH (Dynamic Autonomous Sprawled Hexapod). It was able to reproduce the same behavior as seen in roaches and geckos.

"This work is a great example of the amazing maneuverability of animals, and how understanding the physical principles used by nature can inspire design of agile robots," Fearing said.

This video is not supported by your browser at this time.
A wild-caught gecko, H. platyurus, performs a high-speed inversion while running on a leaf in the rainforest of Singapore. Left panel shows bottom view and right panel show top view. The first sequences are real time. The second sequences are slowed 10X.

Mongeau and Brian McRae, an undergraduate bioengineering major, analyzed the mechanics of the ninja-like maneuver and discovered that the cockroach, an American cockroach (Periplaneta americana), wasn't merely falling over the ledge. It actually ran at full speed toward the ledge, dove off, then grabbed the edge with its claws – sometimes using only one leg – and swung like a pendulum under the ledge, retaining 75 percent of its running energy.

This pendulum swing subjects the animal to 3-5 times the force of gravity (3-5 gs), similar to what humans feel at the bottom of a bungee jump, Mongeau said.

Full looked at trapeze artists as well as other animals to find a comparable behavior, and found only one well-studied similarity: the tree-swinging behavior of gibbons.

These studies of cockroach and lizard behavior are a hallmark of Full's biomechanics teaching laboratory, where undergraduate and graduate students put animals through their paces to determine how they walk, run, leap and maneuver. Recently, Full and his students discovered that geckos use their tails to remain upright in midair, stabilize their body during leaping and even steer during gliding. Now, they are focusing on other body parts – abdomens and appendages such as antennae and legs.

"All this must be put together into a complete package to understand what goes into these animals' extraordinary maneuverability," Full said.

Aside from helping scientists understand animal locomotion, these findings will go into making better robots.

"Today, some robots are good at running, some at climbing, but very few are good at both or transitioning from one behavior to the other," he said. "That's really the challenge now in robotics, to produce robots that can transition on complex surfaces and get into dangerous areas that first responders can't get into."

Explore further: Hearing capabilities of bushcrickets and mammals

More information: dx.plos.org/10.1371/journal.pone.0038003

Related Stories

Berkeley robot uses tiny, spiny toes to climb cloth

Oct 10, 2011

(PhysOrg.com) -- Scientists working in robotics know that nature holds the best ideas for making robots that can perform with speed, agility, and efficiency. At University of California, Berkeley, the Biomimetic ...

Cockroach inspires robotic hand to get a grip

Jan 10, 2011

No one thinks twice about picking up a cup of coffee, but this task has vexed robots for three decades. A new type of mechanical hand developed by researchers at Harvard and Yale promises to solve this problem. ...

Cockroaches offer inspiration for running robots

Dec 28, 2009

The sight of a cockroach scurrying for cover may be nauseating, but the insect is also a biological and engineering marvel, and is providing researchers at Oregon State University with what they call "bioinspiration" ...

Recommended for you

A vegetarian carnivorous plant

8 hours ago

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

Telekinetic
1.8 / 5 (5) Jun 06, 2012
If I had to guess what evolution has in store for us, it may very likely be an amalgamation- Homo Sapiens Americana. Maybe Kafka knew more than he realized.
MandoZink
5 / 5 (2) Jun 06, 2012
Nah. Were just too far away from where the wise ones emit the blue bubbles of lust. We'll never reach that pinnacle of antennaed agility. (Venus on the Half-Shell, Kilgore Trout)
Though I wouldn't mind some more moldy cheese.
nuge
not rated yet Jun 06, 2012
The fuck are you guys talking about?
Burnerjack
5 / 5 (1) Jun 06, 2012
All I can think about is the MTV short "Joe's Apartment".
PussyCat_Eyes
Jun 06, 2012
This comment has been removed by a moderator.
MandoZink
5 / 5 (2) Jun 06, 2012
The fuck are you guys talking about?

Have you not read "The Metamorphosis" by Franz Kafka? Look it up. It is an excellent, rather quirky, classic work of fiction. A literary must-read. Academically macabre tale of waking up to discover you are now a large cockroach.

"Venus on the Half-Shell" by Kilgore Trout (actually Philip José Farmer) is an outrageous sci-fi black-comedy saga. It also eventually involves cockroaches, but I won't spoil it for you. Funny and bizzare.
PussyCat_Eyes
1 / 5 (2) Jun 08, 2012
LOL....my boyfriend complains about the first apartment he moved into. It had been freshly painted, so he didn't notice the smell of Raid, and about 4 months after he moved in, the cockroaches moved back in also. He said that the damn things even crawled through the keyhole in the door into his apartment and they were marching in single file across the ceiling. One night he turned on the kitchen light and they all vamoosed into their hiding places except for one.
He sprayed under the sink and tub, he sprayed everywhere but couldn't get rid of all of them. And they just kept a'comin. Turns out that all the other apartments in the building were infested, and every time they were fumigated, they would run to his. So, he had to pay to get rid of HIS roaches and it still didn't do much good. I had heard that city roaches are the worst. But I laughed so hard and was in tears when he told me about it. I had always lived in the suburbs, so I didn't know much about cockroaches, thank goodness.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.