New Homes for Ants: socialism in insects!

By Paul Robinson - 19 Jul 2016 21:5:0 GMT
New Homes for Ants: socialism in insects!

The explorers of old discovered new sites for colonies, but never as efficiently as these ants, who seem to have the exploring and colonising business off pat!.Experimental image; Credit: © Thomas O’Shea-Wheller

The ant was admired by Solomon, but are they any good at finding the dream of many worldwide, in many countries - a new home? The obvious answer should lie with the house-hunting ant, Temnothorax albipennis. This is a small myrmicine species with nests made of tiny sand grains in rocks. Europe is its home, often in warm rocky places such as near the shore, where cracks in rocks can be colonised b ut it has proved to be the ideal model ant. Researchers have proved it tends to turn left, which helps when you have a maze-like colony, and uses a process called tandem-running to teach new girls the tricks of the trade as far as foraging is concerned.

Enough chat. The name of this paper, published yesterday, was Migration control: a distance compensation strategy in ants. This research uses the tandem running system to investigate how far ants will travel in tandem and how many workers will be involved. Predation, extreme temperatures and several other dangers face the house- hunters when they remove. Colonies automatically engage more workers for longer distances. Each individual seems to encounter others at a rate that determines the numbers to be involved. Decentralised control cold well prove to be very adaptable in the habitat involved, as the unwritten rules are very simple.

You could call these behaviours coordinated group reactions. They certainly appear to be the basis of success among many eusocial insects. 30 lab ant colonies were used here, with queen, a few hundred workers and < 56 brood (eggs and pupae) forming each set.They were presented with ideal homes at various distances and the time taken to reach a quorum of sufficient individuals at the new site measured.

• The experimenters were Thomas A. O’Shea-Wheller, Ana B. Sendova-Franks, and Nigel R. Franks of the Universities of Bristol and the West of England. Their measurements of nest discovery nearby at a mean of 11.94 minutes, 1st tandem run at a mean of 32.80 minutes and quorum reached at a 69.26 minutes show a relatively rapid and smooth running system. Even the furthest nest was reached with a mean of 115.57 minutes.

• By increasing the number of tandem runs, even quite long distances could be covered to reach a desirable nest site. But perception by individuals plays a remarkable role here. Ants in this experiment were led to new nests, but natural explorers would be needed in a challenging environment. Less positive would be reverses tandem running, removing the colonists back to the old nest. However, this behaviour seemed not to affect the time of reaching the necessary numbers or quorum in the new nest. The risks of removal were reduced significantly by this modification of tandem-running. The time taken is crucial in this rocky habitat and the decentralised, self-organised nature of the response, which could easily be in emergency conditions, was the key to efficiency of working. The social animals can be studied more closely than ever, realising how relevant this behaviour is to any colonial animal.

The other side of ants concerns some jumping jacks that nobody would want to keep in their laboratory. Read and wonder at these Spartan warriors of the ant world in The nightlife of bull ants.