GREEN tree ants, Oecophylla smaragdina, don’t leave their dead lying around.
I’ve been watching some workers suck-dry meat left on the front veranda of the house I’m minding in central Queensland. Occasionally there is a dead ant or two; some even squashed after attempting to attack me.
Anyway, the dead ants are never just left where they fall, but rather are picked up and carried away by other worker ants.
I’ve read that harvester ants carry their dead back to the nest and stack the bodies up in little piles.
I wonder where the green tree ants I’ve been watching take their dead.
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Notes and Links
“And they do stack their dead in all kinds of interesting ways… They stacked dead bodies up in intricate little piles that get rearranged on a more or less constant basis.” http://www.npr.org/templates/story/story.php?storyId=6603664
The photograph is of some of the ants I’ve been watching.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Apart from the fact that Green Tree Ants inflict nasty bites, where indeed do they go when dead.
Last year at Halls Creek I finally observed where dead birds go – totally consumed by ground ants.
Since we know of no fossil accumulations of ants in sedimentary strata, dead ants must be recycled, and that suggests ants are carnivores ?
Louis
“ants are carnivores”
Bingo
Actually when I was young (er) I took a great interest in entomology specially in ants,
and watched them endlessly, until puberty kicked in, then my interests changed.
Anyhow, I can tell you that they indeed dragged into the nest their deceased
comrades if they were near enough.
What happened after, I don’t know, Jennifer could advice on this.
Well they are tree ants so they probably would normally look for a tree in which to bury their dead. But then they are green tree ants, so in that case they will probably take the bodies over to the nearest IPCC ‘cash for biomass’ customer service depot and sell them to be incinerated in CO2 friendly manner at the local ant community power station.
As the weather warms and ants get more active our jumping ants go on the attack more readily. Friendly little things.
For some reason the echidna isn’t interested in them and consumes huge amounts of a much smaller, benign sort. Always the way.
Marcus, how could you tell when the ants reached puberty?
spangled drongo
“how could you tell when the ants reached puberty?”
I thought I was talking about my own puberty, but English being my fourth language it is possible that I made a booboo, if that’s the case, I apologise, will try to do better in the future.
Cheers
Marcus, I see the ants tenderly carry off their fallen comrades, but I don’t see where they take them. The colony’s nest is up a tree and huge. I’m not about to touch it.
Louis, Were the birds consumed where they fell or carried off in bits? And interesting comment about sedimentary strata and ants, so you think they eat their dead?
Marcus,
I was just being a smart arse. I was going to add that post puberty ants would be more interesting than pre puberty.
Jen,
the green ants further south are a different species and carry a potent formic acid syringe.
All ants are very civilised, organised and purposeful it seems. But they don’t seem to be able to change their ways to save themselves.
Jennifer
Dead birds were carted off in bits to some underground nest.
Ants in sedimentary strata – fossils do not normally form in an active biosphere – everything is recycled. Fossils form when life forms are quickly taken to an alien environment which stops decay etc. Hence we do not see accumulations of dead ants or dead birds – and if the ants tend to pick up their dead, then indeed where are those dead ants taken to? Or do they decay inside the next, or perhaps consumed by their mates. Of course while we might understand where the ants go, where the uncles go is another matter.
The late physicist, Richard Feynman, described an ant experiment that he performed in his kitchen. Ants had invaded his cupboard, and Feynman wanted to deal with the situation in a non-lethal way. He put a tiny bit of sugar on the floor. Then, using a scrap of paper, he chauffeured the cupboard ants–one at a time–to the sugar on the floor. After some time, the ants’ chemical trail from the cupboard evaporated, leaving only the trail from the sugar on the floor to the ant nest. When that sugar was gone, the ants lost all interest in Feynman’s kitchen. I thought that that was an elegant way to demonstrate the existence of the ants’ food trail chemicals without having to analyze the pheromones themselves.
Inspired by Feynman’s ingenuity, I co-created an ant puzzle on the way back from a day-hike. Mathematician and fellow hiker Dean Hickerson and I had been discussing Feynman’s experiment, and the utility of base-3 ant messages for mathematically inclined ants. I conjectured that the problem was solvable in base 2. Dean was the first person to solve the puzzle. Here’s a more formal statement of the problem.
Binary Ants leave repeating patterns of 1’s and 0’s instead of chemicals in their food trails. If a foraging ant stumbles onto the binary trail, she’ll quickly determine which way to turn in order to reach the food. She won’t waste time and energy heading back towards the nest, thinking that the food is there. What is the minimum number of binary digits in the ‘unit cell’ of the repeating message?
What, no takers? Not even Green Davey? Clarification. If all foraging ants stumbled across the binary food trail from the same side, then a string of 1’s could mean: Turn left if you want to find the new food source. Similarly a string of 0’s could mean: Turn right. But we’re interested in the general case, where a foraging ant could approach the binary food trail from either side.
This mathematical problem really is relevant for the study of animal behavior. Example. When search-and-rescue dogs stumble across the scent plume of a lost hiker, how do they know which way to turn? The dogs cross the scent plume in 2 or more places. Then they turn in the direction where the scent plume is narrower. But is this approach universal for sniffers throughout the animal kingdom?
We are reading. If not commenting.
Now it’s time to end the suspense. The ‘unit cell’ of the binary food trail message must have at least 6 digits.
Example: 011010. The zeros at the ends serve as boundary markers, in the same way that spaces and periods act as walls to separate one sentence from the next. A foraging ant who stumbles across the binary food trail message would see a repeating pattern like this:
…001101001101001101001101001101…
or like this:
…101100101100101100101100101100…
if she approached from the opposite direction.
Using a convention established by royal edict, the worker ant would zoom in on the simple 4-digit message walled off by any given pair of “00”s, and then turn in the direction of the “11” to go to the new food source.
I almost forgot to answer the question raised in this thread’s title: Where do dead ants go?
Answer: They’re broken down into their component 1’s and 0’s, and recycled!