Researchers took a raft structure made of thousands of ants (like one seen in the wild floating down the river) and dropped them into liquid nitrogen. The liquid nitrogen froze every ant, their position, and the overall structure exactly in their place. However, while it froze the ants themselves, it also froze the tiny air bubbles located inside the structure, between the ants themselves. Using an electron microscope, researchers took the raft apart ant by ant. By doing this, they said "We were surprised at just how waterproof raft was -- its ability to repel water and keep afloat" (Gammon). Does anyone else think this experiment was quite clever. I was wondering how you would be able to examine a ant raft without disturbing them. Liquid nitrogen makes sense at it would literally freeze them within a second (or less), keeping in tact the structure itself. It was interesting to note that researchers noted that by adding soap to water the raft was in, would reduce the surface tension and would sink the raft. This is no surprise at it also works if you put a paper clip in water (which will float on the water tension), but with added soap there is much less water tension (the paper clip sinks). Also, apparently the queen can sometimes be found on the raft as well. When the queen is located on the raft, a tighter ball of ants surrounds her, protecting her. It amazes me the waterproof ability of these ants. They are able to make the structure float and be completely waterproof.
Source: Gammon, Katharine. "Fire Ants Assemble as a 'Super-Organism.'" Inside Science News Service. Fox News. 25 April 2011. Web. 26 April 2011.
Picture source: Rifdhan. Fire Ants. 27 Apr. 2011. Picture. Flickr. Web. 13 May. 2011.
I think the experiment they used to see how the raft worked was very clever. How else could they have done it? I am surprised that the ants are able to build such a structure.
ReplyDelete