Ants In Space
Some experiments carried out on the ISS can only be done in its unique micro-gravity environment. However, there was one that was specifically designed so that you could try it out at home.
Ants in Space (technically know as Commercial Generic Bioprocessing Apparatus Science Insert-06) was carried out in January 2014. It involved observing how ants moved around in different sized areas when there was almost no gravity. An equivalent experiment had to be carried out on Earth for comparison; and instructions were provided on how anyone can do it themselves (aimed at American K-12 school children).
There are actually two different sources that you can use for guidance on performing the experiment - Bio Ed online and a site by Prof. D M Gordon of Stanford University. Considering that they're on the same topic they're surprisingly different - with BioEd online being simpler and the Stanford site providing more detail.
Both provide PDF guides and have the same basic sequence:
- Make the experimental chamber
- Gather some ants
- Put the ants in the chamber
- Open the barrier to the first area and observe the ants
- Open the barrier to the second area and observe the ants
In truth my attempt was not particularly successful - in that I didn't get a result that matched the NASA experiments (scroll to the end for the results). Still, I did get some ants in a chamber, and you might be able to learn from my mistakes to get a better result.
Making the Experimental Chamber
This is the first point where the two guides are fundamentally different. BioEd online provides a template to print out and follow - just suggesting that you might draw a smaller sized grid for small ants. The Stanford guide also provides a template, but says that the size of the chamber needs to be adjusted for the size of the ants - being an 8x6 grid where each square is 10% larger than an ant in length.
I followed the Stanford guide. The ants I found seemed to be about 5mm long, so I made the grid squares 6mm (5mm + 10% = 5.5mm). Unless you intend to upload your results to the Stanford site, my advice is to save yourself some effort, and just print one of the templates and leave it at that.
Why is my experiment chamber down in the corner? I borrowed the glass top from a picture frame, and it was easiest to cut the size of the foam board to match it.
Gather Some Ants
I luckily(?) have an ant colony in my front garden; but I had some failed attempts at putting out enticing food and trying to sweep them onto a piece of paper. It is much easier to use an aspirator. This is essentially a container that you suck the ants in to.
They seem quite cheap to buy, but I made my own with a spare film canister and some straws. You need to drill some holes in the lid, and to make sure that they are a snug fit with the straws. If you have a bendy straw for the one that you suck on (or some flexible hose), then that would make it much easier to use. Place a clean piece of cloth over the end that you are sucking through to stop any ants/soil/dust.
The operation is straight-forward. Point one of the straws at the ant (the longer of the two in my version), and then suck air through the other one to hoover them up. Try to get them when they are on concrete/fencing to avoid picking up grass and dirt. You are looking to get 30-40. You will look ridiculous.
Put the Ants in the Chamber
This is where any children carrying out the experiment will need some help. Ants will escape. I had one failed attempt where the ants were too lively and, despite being a grown man, having 30 ants crawling over my hands was slightly unnerving.
The guidance suggests putting them in the fridge for 5-10 minutes. It didn't help the first time, but it seemed to help the second time. Even then a couple escaped and were crawling over my hands as I tried to seal their sisters in. My advice is:
- Prepare yourself for escaping ants.
- Have the experimental container resting on the floor - especially if you are using a glass cover.
- Use a large paper funnel.
- Have a large opening to the funnel (the end that guides them into the experiment chamber) and squash it down to an oval shape - aiming to fill the entire gap.
Opening the Barriers
The ants I gathered seemed to only be exploring the areas in order to find a way out. I probably didn't help by forcing them out of the 'nest' area. Leaving them for a longer period of time in the 'nest' area before starting might allow them to calm down and follow more natural exploring patterns.
The Stanford guide recommends observing for at least 5 minutes after opening each barrier.
Recording and Video Editing
I used a webcam pointing down at the chamber, and recorded the result using VLC Media Player. You choose Media > Open Capture Device, then click on the little arrow that is part of the play button and choose Convert. Play around with the settings first.
I tried editing the video using Blender, and it's a really good free tool. In the end though I took it into Adobe Premiere because of some issues with frame rates.
As mentioned at the beginning, my ants did not follow the behaviour shown in the NASA videos (available to watch on the BioEd online site). They were genuine ants though, behaving in a way that they deemed appropriate, so I guess that the results are still valid. They were just responding to different conditions.
There is also a huge clump of grass and twigs that shouldn't be there. As advised in the 'gathering' section, if you try and get the ants when they're on concrete then you can reduce this. Once there's unwanted bits in the aspirator, you're going to find it very difficult to separate out.
So, what should happen? The guidance suggests several behaviours to look out for, but mainly it seems that high density leads to each ant searching a smaller area. Maybe not unexpected, but there are other things to investigate, and ultimately you'll have carried out an experiment also performed by astronauts in orbit.
The ants were released back to where they came from unharmed.