It’s classic farming folklore: If the cows are lying down, it’s time to batten down the hatches. So is it true that they can predict rain? A recent study at the University of Arizona found that lying cows conserve heat—since rain is often preceded by a sudden drop in temperature, they may assume the position to keep warm as a shower nears. (They may, however, just be relaxing over some delicious cud for unrelated reasons.)
Plenty of other species have reputations for fortune-telling too. This is mainly because they can detect infrasound: noise frequencies so low human ears can’t perceive them. Thunder and earthquakes emit infrasound waves over long distances, as happened in 2004, when a tsunami devastated Thailand. Before the wave made land, herds of elephants— which use infrasound to communicate—spontaneously fled for higher ground. Sharks, meanwhile, can detect changes in ocean pressure, which, theoretically, includes those caused by impending storms. They’re known to avoid hurricanes by making a beeline for deeper water.
Which answers an additional pressing question: No, a sharknado cannot happen.