Rock ants refuse to live in any old hole in the ground, and researchers from the University of Bristol have been finding out how they choose between a des res and a hovel.
Temnothorax albipennis have been previously shown to pick the better of two potential nest sites even when it is nine times further away from their current abode than the less salubrious residence. If ants decide a nest site is a good place to settle down they often return to their soon-to-be former home and recruit friends.
A nest is chosen by the number of ants in a potential nest reaching a quorum, but most ants appear not to visit both sites, say Elva Robinson and her colleagues.
They fitted micro-transmitters to every worker ant in nine colonies housed in artificial nests. Each colony contained between 100 and 200 workers and larvae. The team destroyed the ants’ homes and gave them a choice of a good, far-away site and a worse, closer site to move to. Chip readers on both potential nests recorded ant coming and goings.
“Each ant appears to have its own ‘threshold of acceptability’ against which to judge a nest individually,” says Robinson (press release). “Ants finding the poor nest were likely to switch and find the good nest, whereas ants finding the good nest were more likely to stay committed to that nest.”
This contrasts with previous assumptions that ants compare nests, the team write in Proceedings of the Royal Society B. Ant house hunting isn’t perfect though, in this study only four of the nine colonies chose the far-away, ‘good’ nest, with three putting up the ‘home sweet home’ signs in the poor site and two splitting in half and moving into both.
Tracking bugs so tiny they fit an ant – Sun
Transmitters show house-hunting ants have gift for locating a des res – Times
Ants ‘go further for better nest’ – PA
Ants’ home search habit uncovered – BBC
Photo: Elva Robinson