Stories tagged ants

What, I can only lock this from the outside?: Scientists have observed behavior in ants in Brazil where a small group of ants sacrifice themselves each night for the good of the colony by covering the colony entrance from the outside, leaving them outside at night exposed to all sorts of natural forc
Courtesy Fir0002How do you secure your home at night? With a deadbolt lock? Switching on some high-tech electronic security system? A pit bulls (without lipstick)?

Whatever you do, it's probably not as problematic as what a few ants do each night in Brazil. Researchers have observed that one to eight ants from a colony each night sacrifice themselves for the well being of the colony. They stay above ground pushing sand over the entrance to the colony to protect their peers from predators during the night. Because they're left outside, they most often die in the night, either from freezing in chilly temperatures, getting blown away in high winds or being a midnight snack for a predator.

A typical ant colony in Brazil can number over 100,000, so the few ants lost each night for security is not a huge mathematical loss. How exactly the night workers are selected isn't known for sure, but researchers think they're probably older ants who are approaching the end of their natural life span.

Tags : ants, Brazil, cooperation, sacrifice, insects, hive mind

read more... | add a comment | share

Help me you ants: A new study shows that acacia trees in Africa need to have both the ants that protect them from predators and the predators themselves to thrive. Take away one component, and the trees themselves start to look sickly.
Courtesy WikipediaMighty acacia trees tower and spread across the African skies. Little ants scramble about as a protective army. Without each other, they’re nothing.

That’s what ten years of research is confirming. Scientists have known for a long time about the symbiotic relationship between the big trees and the little bugs. The trees give the ants a place to live. The ants bite and pester large animals that try to eat the tree’s leaves and limbs.

But what happens when the conditions get reversed?

After ten years of study, we’re starting to get some answers.

With the numbers of large animals in Africa in decline, researchers thought they’d try to find out, on a limited scale, what the impact would be of fewer creatures bothering the acacia tree.

Fences were set up around some trees that prevented large animals from feasting on the trees.

Even after just a few years, the trees were looking rather ragged and their growth rates slowed down. What was going on?

The trees no longer had need to take care of the ants. They didn’t produce as much nectar that the ants feed on and they had fewer, smaller thorns for the ants to live in. Consequently, the ants started to abandon the trees for other locations, giving way to other insects that were damaging the trees.

While the original “mutualism” relationship developed over a long period of time, researchers point out that it can break down in a quick amount of time.

Researchers are going to take this experiment to one more level. They’re going to “reverse” the reverse process on some of the fenced trees, taking the fences down and seeing how quickly, if at all, the ants come back to the trees if the large animals start eating the trees’ greens.

What do you think of all of this? Share your thoughts here with other Science Buzz readers.

Tags : Africa, ants, mutualism, acacia trees, symbiotic relationship

read more... | add a comment | share