Saturday, June 09, 2007

Saturday Ant Facts

All of the following are taken from the Wikipedia article on ants. Things I never knew.

- There are more than 12,000 species of ants with more diversity of species in the tropics.
- Ants are not native to Hawaii.
- Ants evolved from waspoids about 150 million years ago.
- Ants lack lungs and a heart; their central nervous system is mostly a column of nerves, similar to the spinal column in humans.
- In addition to their compound eyes, they also have three small "oceli" on the top of their heads for detecting light and dark. They can aee polarized light and use it for geolocating themselves.
- It is estimated that, pound for pound, they constitute something between 15% and 25% of all terrestrial animal biomass.
- The genetic system in ants is "haplodiploidy" which means there are no sex chromosomes, and the sex is entirely determined by the number of chromosomes: males are haploid and females are diploid.
- Ants communicate through chemical signals sensed in the antennae, and unlike us they are able to smell in stereo and use that information spatially.
- Ant males have no fathers and no sons; their genetic material is entirely derived from their mothers.
- Most ants bite for defense but fire ants are unique in having a poison sac. Jack Jumper Ants found in - - - Australia have stings that cause several fatalities yearly.
- This one is a little scary: "ants may be the only group of animals besides primates and some other mammals in which interactive teaching behavior has been observed".
- Ant societies exhibit a wide variety of diversity. Some, like Protestants, are practically solitary; others are well-known for their aggressive warlike ways. War seems to be perfectly natural and endemic among some ant species and sugar ants are famous for their aggressive sidewalk battles which may leave thousands of ants dead. Some enslave others; very similarly to the Ottoman Emperors, Amazon ants are incapable of feeding themselves and must rely on captured slaves from other species to survive.
- Some ants farm fungus and some farm aphids.
- Many species of birds exhibit a peculiar behavior called "anting", in which they pick up and drop ants on their wings, which is not fully understood.
- Siafu ants function as natural insecticides: they will completely clear a field of insect pests and then move on.

5 comments:

chuck said...

I was just browsing through one of E.O. Wilson's books at the bookstore. He is an ant specialist and so I saw the charts about relative bio-mass. Pretty amazing, eh? In some parts of Finland and in tropical regions ants are an even greater percentage of the total. There were also several of Wilson's papers on 'caste' among worker ants, where he attempted to find ways to recognize finer divisions in ant society.

MeaninglessHotAir said...

I've always wanted to read Wilson's huge tome on ants.

I've always wanted to read that huge tome on gravity too.

Another interesting tidbit from the Wikipedia article: the leafcutter ants have evolved very fine castes for the purpose of cutting pieces of leaves into different sizes ("I'm the 1 mm caste!").

chuck said...

I've always wanted to read that huge tome on gravity too.

I assume you mean the tome by Thorne, Misner, and Wheeler. I found it a hard read because it feels like the authors are always going "Oh, wow, far out" and trying to avoid mathematical abstractions. The book *was* published in 1973, after all. If you have some mathematical background, I think Wald's text goes further faster with less annoying verbiage and is all together easier to read.

MeaninglessHotAir said...

chuck,

Do you mean "Space, Time, and Gravity"?

chuck said...

No, General Relativity. It is slightly more recent (1984) and is commonly used as a graduate text.