Do you know if ants can see germs?

Question

the really small ants that is. I've always wondered this, I mean they are so small and close to the surface and everything must look so much bigger to them. If they can see germs, would germs be as small to ants as ants are to us?

Answer 1

I think that's a good question.  Humans are on the scale of a few meters, ants a few milimeters, and bacteria a few micrometers.  That means that humans are about a thousand times larger in length or height than an ant, and an ant is about 1000 times larger than a bacteria.  Non-bacterial germs are are actually much larger than bacteria. So if everything were to scale up, a bacteria should look the size of an ant to an ant.  

However, not everything scales up like that.  Even though ants are much smaller than humans, light waves do not scale up like that.  A visible light wave is about half a micrometer, so just barely larger than a bacteria.  That's why bacteria are so difficult to see even with the best light microscopes (most pictures you see of bacteria are taken with electron microscopes, which deal with much smaller wavelengths).  The resolution of a microscope is limited by the size of light wavelenths and something called the "numerical aperture" of the lens that is trying to see the object.  High powered microscopes are designed to have the maximum numerical aperture possible, but both ants and microscopes are limited by the laws of optics as to what they can see.

Now unfortunately, I do not know much about ant eyes, so I do not know what their limiting numerical aperture is, but I would guess that they probably are not designed like a microscope to see little bacteria.  I would think that they rely much on their antennae as feelers to "see" little things, and their compound eyes are used to see big things far away from them.  

I think it's a good question and obviously I don't have a definitive answer for you, but I think it's likely that ants are limited by optical physics as to how small they can see, and I'd bet that they can't see bacteria.  

Answer 2

No germs are microscopic.They are way to small...