Ants can sense earthquakes a day in advance

Ants can sense earthquakes before they strike and the tiny insects suspend their normal activity till a day after the quake, new research has found.
Researchers have discovered that red wood ants prefer to build their colonies along active faults, fractures where the Earth ruptures during earthquakes, in Germany.
They found the ants change their behaviour significantly prior to the quake and resume normal functioning only a day after the earthquake.
Gabriele Berberich of the University Duisburg-Essen in Germany has counted more than 15,000 red wood ant mounds lined up along Germany's faults, 'LiveScience' reported.
Berberich and her colleagues, for three years, tracked the ants round the clock with video cameras, using special software to catalogue their behavioural changes.

During the study period, 2009 to 2012, there were 10 earthquakes between magnitude 2.0 and 3.2 and many smaller temblors.

The ants changed their behaviour only for quakes larger than magnitude 2.0, which also happens to be the smallest quakes that humans can feel.
While during the day, ants busily went about their daily activity, at night the colony rested inside the mound, mirroring human diurnal patterns, Berberich said.
However, before an earthquake, the ants were awake throughout the night, outside their mound, vulnerable to predators, the researchers found.
Berberich noted that normal ant behaviour did not resume until a day after the earthquake.

Berberich suspects the insects pick up changing gas emissions or local shifts in the Earth's magnetic field.
"Red wood ants have chemo-receptors for carbon dioxide gradients and magneto-receptors for electromagnetic fields," she said.
"We're not sure why or how they react to the possible stimuli, but we're planning on going to a more tectonically active region and see if ants react to larger earthquakes," Berberich added.
The research was presented at the European Geosciences Union annual meeting in Vienna.