Ants Have Higher Sense of Smell

Completing the first full map of the olfactory system of ants, researchers have discovered that ants have a dramatically more advanced odor-sensing capability than other species with four to five time more odor receptors than flying insects such as moths, mosquitoes and honeybees.

Ants Remember Enemy Scent

A new study using tropical weaver ants (Oecophylla smaragdina) shows that ants remember the particular chemical odor of other ants not native to their colonies and are able to pass along that "chemical signature" to their nest-mates as a collective memory for defense of the colony.

Invasive Ants Vanish

One of the world's most invasive species, colonies of the Argentine ant (Linepithema humile) are collapsing and disappearing from New Zealand without human intervention, with speculation that low genetic diversity has made then susceptible to widespread disease.

Meat-Farming Ants

Entomologists studying the Melissotarsus ants of Africa and Madagascar believe they raise the smaller armored scale insects within their own burrows as a direct food source, the first example of pure animal husbandry in the animal kingdom.

"Zombie" Ant Fungus

A newly discovered fungus (Ophiocordyceps camponoti-balzani) in the Brazilian rain forest creates "zombie" ants by infecting their brain and directing them to an optimal place for the fungus to grow and spread its spres.

Fossils Reveal Zombie Ants

The discovery of a fossilized leaf has revealed a very distinct scar left by an ant infected by an ancient parasitic fungus similar to modern Ophiocordyceps unilateralis, which takes over the minds of the ant hosts and forces them to leave their colonies and seek out a plant that provides the ideal conditions for the fungus to reproduce.

Acacia Plant Controls Ants

The African acacia plant has been found to secrete chemical signals that send the ants living on them into a defensive frenzy when under stress, revealing a rather complex symbiotic relationship between plant and insect.

Ant Colony Spans Globe

Argentine ants (Linepithema humile) living in Europe, the United States and Japan recognize each other as belonging to a single interrelated super-colony spanning the six populated continents.

Cheating Ants Detected and Caught by Other Workers

Researchers at Arizona State University have found that worker ants attempting to mate while a queen is present signal themselves chemically, and are prevented from doing so by other worker ants.

Typically, the queen is the sole reproductive female in an ant colony, with the population filled with various male and female workers. Scientists found that when female ants (Aphaenogaster cockerelli) other than the queen are fertile, they emit a chemical hydrocarbon to attract a mate. This hydrocarbon is detected by nestmates, who will proceed to physically restrain the female from mating in favor of the queen. These hydrocarbon signals are also used to discriminate between eggs laid by the queen and those of other worker ants.

Experiments using a similar synthetic chemical compound applied to workers attracted aggression from others in colonies with a queen but it failed to have a similar effect in colonies without a queen, where female workers lay eggs until a new queen is obtained.

These results appear in the January 8th online edition of Current Biology.

Photo: ScienceDaily