Population Control - Atta - home set up

[RichardP]

I have an Atta colony and, as you might imagine, I am thinking about population control alongside housing expansion solutions.

I read an article that was in the name of, I think, The Cincinnati Zoo and part of the article discussed population control. In a nutshell it said there were two options:

1. Destroying ants (in significant) numbers periodically (the preferred method)
2. Restricting the amount of substrate (leaves etc)

Now I couldn't bring myself to use option 1.

If I was considering option 2, and I want a healthy, happy colony, but I want it to grow at it's slowest rate.... How often should I be supplying/withholding substrate?

Does anyone have any thoughts?

Thanks

[Deansie26]

That's a tricky one, I know exactly the problem. I was looking after a few colonies over Christmas for Andrew and just having them for the couple of weeks made me realise just how much he must have to limit there intake or they could become unmanageable very quickly.

Guess you could give them the same set amount every time and manage the amount by tracking how quickly it's all consumed. I've a habit of always topping them up with leaves, there never without but I'm not concerned at this point about size.
Even if you limit food,I'd imagine a healthy colony of Atta may eventually need a cull.

[Acromyrmexbob]

Colony growth in Atta is an interesting topic. Randy Morgan is a real expert on Leaf Cutters. He has kept them for many years in Cincinnati (hes retired now) but set a real precedent in displaying them so effectively. I met him once in Trinidad when he was collecting at the same time as me on my second trip there. Awkward!!
Before I answer this I need to have a rant!! To be honest my opinion on numbers in Atta is straight forward. If there will be a problem with the size an Atta colony will grow to then keep Acromyrmex. It doesnt make sense to keep a nest of these ants which grow to such impressive proportions if when they start to grow we have to restrict them. Especially when there are other species which remain manageable for so long. Thats like keeping a baby Pacu in a goldfish bowl. We all know sooner or later it will get too big, so why not get a goldfish instead of stunting it and keeping it in a home that is clearly not suitable. If you want Atta, give them a home that is fit for Atta. Adam said on here that he keeps his Atta colonies at sub optimum conditions by restricting the food they get. This in turn restricts their ability to grow fungus which reduces the youngsters they can produce. He admitted that basing observational results on a colony in a lab which is not a naturally behaving colony is possibly flawed.
Okay thats my rant done!
The problem with the 'substrate' method is this. When you have a naturally expanding colony of Leaf Cutters, the workers are gainfully employed as they would be in the wild. They are attending to various housekeeping duties or foraging etc etc. When the resource of space or food or substrate is limited in an artificial way then a proportion of the ants become unemployed. This growing fraction of the population then devotes itself to finding an alternative source of this resource. They will continually try to escape, to bridge the water, to cross barriers etc. It is amazing the ways in which this constant, 24 hour, effort can expose weaknesses in a set up which previously appear perfect. As the numbers increase and this activity increases so, by sheer weight of numbers, they become more and more effective at finding escape routes. Whereas Adam keeps his colonies for research and this is simply a situation which must be managed, I wonder how much pleasure there would be in seeing this escape effort and battling against this army constantly when you want to relax and enjoy them. When things are not right for a captive animal then there is a reduction in the level of satisfaction you experience in keeping them.
The culling method is by far the most effective way. First of all you need to think of the workers as no more important than your cheek cells. There is in fact only one organism in your colony, the queen. All the others will sacrifice themselves in order to ensure her survival. So they are entirely expendable. You basically place their favourite food on the table and when there are masses of ants feeding you stick the whole thing in a bin bag and dump it in the freezer. Done!
But the best method is to accommodate the animal you are keeping and give them a big enough nest tank.
Just realised I have lost myself in the cr*p I have been spouting for the last 15 minutes, sorry, Richard, but you did ask.

[RichardP]

Thanks for the info. You may have felt that was a rant but it's not. It is really helpful insightful information that it is difficult to get from anyone other than a seasoned expert. Of which there are few.

In terms of my own situation, you will be aware that I visited Adam and his collection as part of my preparation and research. Based on the size of his colonies, their respective age, and the capacity of his housing environment I anticipated that my set up would last me at least 2 years.

You have just pointed out that there may be some compromise in how he maintains his colonies and their overall welfare/the effectiveness of the overall set up. Which I wouldn't have been aware of until now.

On the positive side, I have not gone into this enterprise lightly and I still have a host of options to consider in managing things going forward. Now that I can pipe out of the tank I could start to utilise some external nesting chambers with heat/humidity control (I'd be really interested on people's thoughts on this). I could also invest in another aquarium and have them linked (Don't tell my wife - or my bank manager!)

Why did I choose Atta instead of Acro? Well, It's something difficult to explain. It's somewhat spiritual.. or emotional. It's just that Atta, for me, are the ultimate ant. Their colouring has the depth of polished amber, they are a self-assured and graceful. Their little pincers reflect the light like shards of crystal. I love their polymorphic castes. The queen is a leather clad behemoth. They are simply beautiful and engaging.

But, yes it does leave me with a few problems to solve. What you say about limiting substrate is extremely interesting but it doesn't quite answer my question (without wishing to sound impertinent, I'm extremely grateful for the advice and help).

I want a healthy, happy colony, but I want it to grow at it's slowest rate.... How often should I be supplying/withholding substrate

You've clearly explained the possible downsides of withholding substrate but nevertheless there may be a minimum substrate approach that doesn't promote the issues you've mentioned.

Of course the answer could be - don't regulate the substrate feed them every day. And if that were the case then to be honest your concise explanation of the culling process leads me to think that I could achieve that relatively easily (again don't mention to my wife that I'm putting ants in the freezer.)

So, in summary, it might have felt like a rant but you've imparted an enormous amount of incredibly helpful information. Thx.

[Deansie26]

Andrew, could you give us a rough guide of what you consider a decent size colony for Atta and Acromyrmex. Say we use the 15cm cylinders I posted earlier; 1 colder is equal to 1 fungus garden.
So, Atta would have...
Acromyrmex ...

I know it's simplistic but would appreciate your idea.

[Acromyrmexbob]

Why did I choose Atta instead of Acro? Well, It's something difficult to explain. It's somewhat spiritual.. or emotional. It's just that Atta, for me, are the ultimate ant. Their colouring has the depth of polished amber, they are a self-assured and graceful. Their little pincers reflect the light like shards of crystal. I love their polymorphic castes. The queen is a leather clad behemoth. They are simply beautiful and engaging.

That is just about the best description of Atta I have heard. I am an Atta freak as well. They just outshine Acromyrmex.

Andrew, could you give us a rough guide of what you consider a decent size colony for Atta and Acromyrmex. Say we use the 15cm cylinders I posted earlier; 1 colder is equal to 1 fungus garden.
So, Atta would have...
Acromyrmex ...

I would say Acromyrmex has 2 chambers full of fungus and you will be unlikely to have problems with them, Atta should have as many chambers as possible and with them you've reached the ideal colony size when they stop filling them. I made a huge exhibit at Five Sisters Zoo. The nest was a soil filled enclosure approx 8 feet long, 12 feet front to back and around 3.5 feet deep (2.4mx3.5mx1.1m). The colony has been in place for exactly a year and is colossal. There must be half a million ants. This colony will reach the size where it will produce winged sexuals. I would love to build a glazed wall 10cm out from an existing wall in my living room and fill it with soil so a large Atta colony can build 50 fungus gardens and I can see it all! Or put a shelf around a room just down from the ceiling and place nest boxes all around so the ants can fill 30 or 40 chambers and forage through a pipe to another room. I am not accustomed to restricting Atta. The customers who buy these ants from me want big and impressive and shout at me for the first 2 months that not enough is happening. I tell them to wait a little. Sure enough they go quiet. Then I wait a little more, knowing whats coming. And then they get in touch with me to complain about what they should do with all these blasted ants that are everywhere. Fantastic! I genuinely believe that the ideal size for an organism should reflect the size it achieves in nature. Leaf Cutters must be about the only organism kept out of all the animals in captivity where we try to prevent it from growing up by working out ways to stunt it. I spend my professional life trying to work out ways to get them big as fast as possible!

[Deansie26]

I'm sure visitors coming to your exhibits want instant ants, I know when I visited Amazonia a few times and they weren't there I was disappointed.
That surprised me about the amount of fungus you would roughly expect Acromyrmex to have, my first colony had the equivalent of 3 cylinders on fungus but it was a two queen colony. I thought I would fill 6 cylinders easily. Hmmmm, might have to think about using Atta in mine instead.
That wall set up would be great in your house, you would never be out the room though!

[RichardP]

In terms of minimising population growth, which I agree is more important in home set ups than commercial environments, and following on from Andrew's comments above (about "straining" the ants by restricting substrate) , a partial solution/idea has occurred to me.

I have been using apples and brussel sprouts recently and both these substrates have the quality of being "difficult" to harvest.

Therefore you get very busy ants but slower growth than if you were to just keep chucking in privet.

Just a thought.

[Britishants.com]

Here's a thought! If you grow your fungus in pods and the colony are becoming unmanageable, assuming you know where the Queen is, would it not be better to detach a pod of fungus from the unit and open the lid! By default/evolution all the soldiers will run out/at you making them easier to isolate. the fungus and minimums can then be offered to boost other leaf freaks set up! The remaining ants/soldiers can be turfed in to the original container. It would ensure a steady population control without killing the poor buggers! I'm with Uncle Bob on his rant!

[RichardP]

Here's a thought! If you grow your fungus in pods and the colony are becoming unmanageable, assuming you know where the Queen is, would it not be better to detach a pod of fungus from the unit and open the lid! By default/evolution all the soldiers will run out/at you making them easier to isolate. the fungus and minimums can then be offered to boost other leaf freaks set up! The remaining ants/soldiers can be turfed in to the original container. It would ensure a steady population control without killing the poor buggers! I'm with Uncle Bob on his rant!

Thanks, that's an interesting idea.

I wouldn't really be in a position to be supplying fungus and ants to other "leaf freaks" though I don't think.!