Right-left pill bug walking pattern.

[AL]

I was watching MXC on Spike TV today, just for kicks. For those that don't know, it is a show where they play video clips from zany game shows out of Japan, and then offer silly commentary in English. Great show.

 

In any case, they showed a clip from a trivia show in which they asked contestants if it was true or false that pill bugs (or sow bugs or rolly pollys) always and consistently alternate between turning right and turning left each time they encounter a wall or obstacle. After the contestants chose their answer, a University of Tokyo professor came out and said the answer is true that they always, without fail, follow a right-left-right-left-right-left-right (and so on) pattern. They then showed video clips of 3 pill bugs placed inside a maze. Sure enough, each bug went straight until it hit a wall, then it turned right and continued until it hit a wall, turned left and continued until it hit a wall, turned right....etc. All 3 bugs did it.

 

I tried to check this out on the web, but couldn't turn up anything about it. This is very peculiar if true, and I want to know more about this. Anyone know a) if this is true, and b) what causes pill bugs to do this?

 

Edit: Just found out that "woodlouse" is another name for pill bug. Did a search on that and found some info like this:

http://asab.icapb.ed.ac.uk/practicals/woodlice_turning.html

Apparently, turn alternation is a real phenomenon, and woodlice aren't the only creatures that do it. Fascinating. It's like one of nature's earliest problem solving algorithms to help primitive creatures get around obstacles.

[Jordan14]

Well, I never knew that. It's quite strange, does anyone know why?

[Ophiolite]

Well, I never knew that. It's quite strange, does anyone know why?

What are the options:

1. Turn right every time

2. Turn left every time

3. Turn right left right left right

4. Random choice

5. Turn right right left right right left

6. etc

Initial behaviour would be random. 1 or 2 would have you going in circles. No survival value there. 5, 6 and beyond are less likely to arise and are equivalent, on average to 1 or 2.

The battle is then between random and alternating. If we assume woodlice are heading somewhere, an alternating approach tends, on average, to maintain that direction. Random does not. So alernating has a survival benefit.

[Jordan14]

Thank You, Ophiolite it makes so much sense when you think about it.

[Jordan14]

And also I never knew a woodlouse was called a pill bug in America.

[AL]

I wonder if it is possible to design a maze that has a valid solution, but in which strict turn alternation is guaranteed to get you stuck and unable to complete the maze. We'd have to allow for the woodlouse to turn around when it hits a dead end with no real left or right path, but other than that, a strict turn alternation pattern seems like it is guaranteed to eventually yield a solution, even if it's not the most efficient path out of the maze. Maybe some mathematicians or computer scientists would like to take a shot at proving if a strict turn alternation algorithm is guaranteed to get you out of any maze with a valid solution?

 

 

 

And also I never knew a woodlouse was called a pill bug in America.

 

Ha. I never knew a pill bug was called a woodlouse outside of America. They're also called sow bugs, and colloquially, they are known as "rolly polys," or as they are sometimes called by small children who are fascinated by the critter's ball form, "woo-puoys." (rhymes with "buoy.")

[coquina]

They are also called Isopods, and are arthropods, not insects.

http://insected.arizona.edu/isoinfo.htm

 

Look at their little segmented body - they must turn a corner sort of like a marching band. If they are turning left, the left side marks time and the right side runs like hell. Maybe they alternate so that the legs on either side get the same amount of use.

[Ophiolite]

Just to add to the list of names, in Scotland they are also called slaters.

[Mart]

Maybe they alternate so that the legs on either side get the same amount of use.

 

Could be. Woud they need to remember what side did what? If so, by making the distances in the maze larger you could get info on their short/long term memory.

[slickinfinit]

in Canada we incorrectly call them potato bugs lol

[Guest Thomas215]

That's kind of weird.

[Deathby]

I had heard of woodlice, but never realised they were slaters (Australian here)

 

Actually if you place your hand on one wall and keep following that wall you'll eventually find a way out... even if it is the way you came in. I don' think it would be possible to make a 2 -entranced maze that can be solved, but not by simply placing a hand on one wall. Unless of course it was multilayered... hmm didn't think of that one. Then you could just have the trapdoor or stairway in the middle somewhere. I guess that's how video games work haha.

[Flareon]

What if the bug of many names was walking, doing his little left-right-left-right shuffle and I picked him and shook him (don't call PETA) and made him all discombobulated and set him back down. Would he pick up the pattern where he left off? Does he always begin with the left, or is the beginning step random? Im really curious to find out more.

[ecoli]

To be anal...it's not a bug, it's a terrestrial isopod.

[Flareon]

You 'bug' me...