Interesting article. Worth a read - here are a few highlights:

BBC: The study involved recording the movement patterns of different animals (cows, sheep and dogs) – a process known as biologging – on a farm in the earthquake-prone region of the Marches in central Italy. Collars with chips were attached to each animal, which sent movement data to a central computer every few minutes between October 2016 and April 2017.

The researchers found evidence that the farm animals began to change their behaviour up to 20 hours before an earthquake. Whenever the monitored farm animals were collectively 50% more active for more than 45 minutes at a stretch, the researchers predicted an earthquake with a magnitude above 4.0. Seven out of eight strong earthquakes were correctly predicted in this way.

Researcher: The closer the animals were to the epicentre of the impending shock, the earlier they changed their behaviour. This is exactly what you would expect when physical changes occur more frequently at the epicentre of the impending earthquake and become weaker with increasing distance.

Matthew Blackett: Earthquake precursors aren't well documented scientifically. Perhaps they detect pressure waves before earthquakes arrive, perhaps they detect changes in electric field as fault lines when rock starts to compress. Animals also contain a lot of iron, which is sensitive to magnetism and electric fields.

BBC: Positive holes could also cause certain toxic chemicals to appear before quakes. For example, if they come into contact with water, they can trigger oxidation reactions which create the bleaching agent hydrogen peroxide. Chemical reactions between the charge carriers and organic matter in the soil could trigger other unpleasant products such as ozone.

Jiang Weisong, Nanning: Of all the creatures on the earth, snakes are perhaps the most sensitive to earthquakes. When an earthquake is about to occur, snakes will move out of their nests, even in the cold of winter.

BBC: In 2014, scientists tracking golden-winged warblers in the US recorded a startling example of what's known as an evacuation migration. The birds suddenly took off from their breeding ground in the Cumberland Mountains of eastern Tennessee and flew 700km (435 miles) away – despite having just flown 5,000km (3,100 miles) in from South America. Shortly after the birds left, a terrifying swarm of over 80 tornadoes struck the area, killing 35 people and causing over $1bn (£740m) in damage.