Just in time for Halloween, MJ Epps and I have created glowing ants. Like mad scientists, we locked ourselves in our office last week with only the faint glow of a black light escaping under our door. With petri dishes scattered across our desks and our fingers stained with fluorescent dye, we finally ended up with a colony of ants that glowed.
Why glowing ants? We have been trying to figure out what ants eat. What seems like a simple question can be surprisingly difficult to answer for an animal the size of a grain of rice. For a large animal – like a bear – you can check their scat. But ants don’t have much scat to speak of. You could offer ants different types of food to see what they take back to their nest, but it’s another thing to say whether or not they actually digest it. To answer this last question is what led us to create glowing ants.
We stained foods with a fluorescent dye and then fed it to colonies in the lab to see if we could trace it through their digestive tracts. From the picture above, you can see that it worked. This Aphaenogaster worker has a bright red glow emanating from her abdomen, and the glow is coming from her crop, also called the “social stomach.” Incidentally, this is the exact same thing that happens to us when we eat too much candy corn.
Header image: his worker ate something strange. You can see it glowing in her abdomen under a black light. (ant: Aphaenogaster rudis; photo credit: Lauren Nichols).
Have you seen the setup of Simon Garnier? I think that Tapinoma sessile is more transparent with an expanded gaster than your Aphaenogaster (plus he used some paint to mark those with food access, to clearly show trophallaxis)
Yes! Tapinoma glow quite well. Aphaenogaster are much darker, and the glowing was only strong after we used a long exposure. We wanted to know if ants actually digest a particular type of food, so we dissected their digestive tract to look for glowing throughout their entire gut (crop, midgut, hind gut). This is somewhat different from Simon’s experiments, but the glowing dye is nice and fairly easy to use.