Ants count their steps

[Royston]

A recent study has shown that ants actually count their steps to navigate home, rather than using visual clues. To test the hypothesis, they had to cut the feet off of a number of ants, and attach little stilts to another selection, to see if the amputees fell short of their goal, and similarly to see if the 'ants on stilts' overshot their goal home.

 

Please see the livescience article below...

 

http://www.livescience.com/animalworld/060629_ant_pedometers.html

[gib65]

To test the hypothesis, they had to cut the feet off of a number of ants...

 

Man, that sound heartless. Do ants feel pain?

[reor]

That's... frankly MESSED UP! To say the least! Scientists...

 

Humor

Ant: "(counting steps) 34985, 34986, 34987, ... hey Frank!"

Bnt: "Hey Joey! How's the wife and kids?"

Ant: "Great as usual. You look fine! Have you been working out?"

Bnt: "Yes! I'm glad it's showing!"

Ant: "It surely is! Say, do you recall my step count?"

[Mokele]

How do they know it 'counts', as opposed to just moving at a constant speed and recalling how long it has been moving? Such an experiment can't distinguish between this possibility and counting.

 

Do ants feel pain?

 

If you cut an ant's head off, they do just fine, only dying due to dessication or starvation. So that would be a big 'no'.

 

Mokele

[Martin]

A recent study has shown that ants actually count their steps to navigate home' date=' rather than using visual clues. To test the hypothesis, they had to cut the feet off of a number of ants, and attach little stilts to another selection, to see if the amputees fell short of their goal, and similarly to see if the 'ants on stilts' overshot their goal home.

 

Please see the livescience article below...

 

http://www.livescience.com/animalworld/060629_ant_pedometers.html[/quote']

 

that is interesting! Hi Mokele and others,

here is something by the scientists themselves that gives some more detail:

http://stammhirn.biologie.uni-ulm.de/SciencePressNote0606.pdf

 

 

they do trigonometry in effect also, since even after a long zigzag path of perhaps 100 meters, the ant knows how to make a "beeline" direct path for home, and she knows HOW FAR to walk.

 

if she has wandered around for 100 meters and she happens to be 10 meters from the nest, then when she finds some food and wants to go back with it, she will head directly for the nest and go 10 meters! then if (say because of an experimenter's trick) she does not find the nest where she expects, she will start a random search pattern.

 

this is pretty amazing. it is like you go on a right 3,4,5 triangle and you go 3 meters and then turn 90 degrees and go 4 meters, then you know you are 5 meters from "home"

 

pretty good for an ant.

 

this was in New Scientist and also the NY Times

Mokele, earlier today I saw somewhere how they excluded that the ant was calculating based on TRAVEL TIME. Somehow the researchers excluded that hypothesis. If the ant is somehow made to take SLOWER paces, then if it is supposed to go 1000 paces it will still go 1000 paces, even if it takes longer.

 

Good find Snail!

thanks. after I saw your post I found several other articles, google had a bunch earlier today

[Royston]

that is interesting! Hi Mokele and others' date='

here is something by the scientists themselves that gives some more detail:

http://stammhirn.biologie.uni-ulm.de/SciencePressNote0606.pdf

 

 

they do trigonometry in effect also, since even after a long zigzag path of perhaps 100 meters, the ant knows how to make a "beeline" direct path for home, and she knows HOW FAR to walk.

 

if she has wandered around for 100 meters and she happens to be 10 meters from the nest, then when she finds some food and wants to go back with it, she will head directly for the nest and go 10 meters! then if (say because of an experimenter's trick) she does not find the nest where she expects, she will start a random search pattern.

 

this is pretty amazing. it is like you go on a right 3,4,5 triangle and you go 3 meters and then turn 90 degrees and go 4 meters, then you know you are 5 meters from "home"

 

pretty good for an ant.

 

this was in New Scientist and also the NY Times

Mokele, earlier today I saw somewhere how they excluded that the ant was calculating based on TRAVEL TIME. Somehow the researchers excluded that hypothesis. If the ant is somehow made to take SLOWER paces, then if it is supposed to go 1000 paces it will still go 1000 paces, even if it takes longer.

 

Good find Snail!

thanks. after I saw your post I found several other articles, google had a bunch earlier today[/quote']

 

Thanks for clarifying the experiment Martin, the level of detail was lacking with the link I provided. I found this particularly interesting, not only because of the inherent pedometer the ants possess, but it illustrates the 'almost' unorthodox techniques used by science to test a hypothesis...ants on stilts

[reor]

Still, messed up.

 

... If you cut an ant's head off, they do just fine, only dying due to dessication or starvation. So that would be a big 'no' ...

Interesting, but NOT a valid reasoning! Anyway, i'm not sure this applies to ants, but i know it applies to cockroaches. Please, consult your informant or other source to clear your confusion.

I can only clear your bank account.

 

Humor

Ant: "Dude, where's your head?"

Bnt: "(morse-coding with stilts) .-. . .- -.. / .- -... --- ...- ."

Ant: "What? That's messed up!"

[badchad]

I could be way off on this but another thing to consider: Aren't numbers basically a human construct? An ant may keep track of the steps it takes, but I didn't think other animals had the construct of what a "number" is.

[gib65]

I could be way off on this but another thing to consider: Aren't numbers basically a human construct? An ant may keep track of the steps it takes, but I didn't think other animals had the construct of what a "number" is.

 

Why not? Nature provides for whatever it needs. If it needs some mechanism by which it can count its steps, then nature will give it that.

[Mokele]

Anyway, i'm not sure this applies to ants, but i know it applies to cockroaches.

 

It applies to both, as well as wide range of insects. They're not exactly bright animals.

 

Interesting, but NOT a valid reasoning!

 

Wrong, it's perfectly valid. Pain =/= nociception. Pain is a much more complex response, requiring a level of neural complexity that simply is not present in many arthropods.

 

In fact, technically the insect 'brain' is merely an enlarged ganglion, much like the other ganglia throughout their bodies.

 

Mokele

[reor]

Are you trying to tell me they are incapable of suffering, just because their neural system is different to ours? Please explain, i don't know how "pain" is processed. I mean, they react on intense stimuli. Can we be sure they don't "feel"?

[Mokele]

The issue is the difference between 'feel' and 'pain'. Nociception is the detection of noxious stimuli, and is *not* equal to pain. Even bacteria are capable of nociception, and decapitated animals are respond to noxious stimuli. Additionally, at particular doses of morphine, human patients report being aware that something is damaging to them, but not feeling pain or distress. Several lines of evidence point to 'no brain, no pain', namely that pain is a mechanism employed by the brain to allow more efficient learning from noxious stimuli.

 

Given the extreme simplicity of the insect nervous system and the superfluousness of the brain as anything more than an intergration center for sensory information and gross motor control, it seems highly unlikely that most insects can feel something that could effectively be called 'pain'.

 

Mokele

[reor]

Kinda makes sense. Tho, i still believe when something tries to avoid certain experiences it can feel fright, pain, suffering.

[Mokele]

So you think bacteria feel pain?

[bascule]

When I was younger I considered myself something of an amateur myrmecologist. I voraciously consumed anything I could read about ants.

 

Everything I read described the use of chemical signaling (i.e. pheremones) in order for ants to guide themselves around the world.

 

I can definitely see this being used in conjunction with pheremones, but this is the primary mechanism by which ants guide themselves. They leave different types of pheremone trails as they walk which signal different messages (i.e. home is this way, food is this way, etc)

[Martin]

primary mechanism by which ants guide themselves. They leave different types of pheremone trails as they walk which signal different messages (i.e. home is this way' date=' food is this way, etc)[/quote']

 

chemical trails are the primary means except for these DESERT ants

 

it is a case of evolution

 

these ants found that in the hot desert, a pheromone trail evaporates almost immediately and does no good

 

also according to what I read, the food these ants typically find is not a big trove but the lone dead body of some other kind of insect----it is small enough for ONE ANT by itself to carry back

 

so the only information that is useful is the information for that one ant: how to get home.

 

it would be useless for her to lay a trail for other ants to follow, even if she could, because it would not lead them to any food.

 

so the ants had a radically different navigation problem to solve and they evolved a new program

[silkworm]

A recent study has shown that ants actually count their steps to navigate home' date=' rather than using visual clues. To test the hypothesis, they had to cut the feet off of a number of ants, and attach little stilts to another selection, to see if the amputees fell short of their goal, and similarly to see if the 'ants on stilts' overshot their goal home.

 

Please see the livescience article below...

 

http://www.livescience.com/animalworld/060629_ant_pedometers.html[/quote']

 

This is an awesome study, I like it alot. The ants also adjusted the after a new count was made.

 

I'd like for them to go further and figure out whether they're counting a specific leg or if its all of their legs, or a set or what.

[Royston]

When I was younger I considered myself something of an amateur myrmecologist. I voraciously consumed anything I could read about ants.

 

Everything I read described the use of chemical signaling (i.e. pheremones) in order for ants to guide themselves around the world.

 

I can definitely see this being used in conjunction with pheremones' date=' but this is the primary mechanism by which ants guide themselves. They leave different types of pheremone trails as they walk which signal different messages (i.e. home is this way, food is this way, etc)[/quote']

 

The humble ant was the first thing I studied under a microscope, when I was just 6. It was the first time I realised how incredibly small and complex organisms can be.

 

IIRC there are several species of ant, that have adopted a scout...who's sole purpose is to find food, and leaves a chemical trail for the rest of the nest to follow. When the source of food has diminshed, the scout will lead the ants to another source and so on.

 

Silkworm raises a good point, the mechanism that tells the desert ant could be attributed to one or several legs...if a leg is lost, it could effect their pedometer count, that is unless the count is just from the signal going to the leg, rather than the actual leg moving. I'm guessing it's unlikely there is an evolutionary change for lost legs to compensate for the count.

[walrusman]

I could be way off on this but another thing to consider: Aren't numbers basically a human construct? An ant may keep track of the steps it takes, but I didn't think other animals had the construct of what a "number" is.

 

Yeah, it's not like they're counting one, two, three...

 

What's interesting to me is it appears they have a way of dealing with these calculations that rival the average human's grasp of such things. If we could understand exactly how they interpret a "number" and their process of deduction, we might find that humans go the long way around, so to speak, with our math.

 

Also, I wonder if rhythm could be considered. It would explain why slowing them down would still produce the correct route home. You have to count to get rhythm, but maybe that's how they think of math???? Just a thought...

[CurvKyle]

What I want to know is who managed to attach stilts to ANT LEGS

 

They must have one hell of a steady hand.

 

Also, what do you think allows for these ants to adjust their stride depending on the length of their legs? The only thing I could come up with is maybe the various terrain they walk on changes how far they go with each step. Any other ideas?

[iNow]

This is an old thread, but I had a really cool link I wanted to share without starting a new thread for it. This seemed like the best place based on the search results which were returned.

 

 

http://www.gigapan.org/viewGigapan.php?id=27105&window_height=870&window_width=1663

This ant is composed of 400 pictures, and it's magnified 400x using a scanning electron microscope. The ant was given to us to image by Brian Fisher an entomologist at the California Academy of Sciences.

 

 

It's pretty bad ass. You can zoom in and check out different parts of the ant from really close up.