The Big Reason This Popular Cow Myth Is False

Have you ever been told that a herd of cows lying down in a field is a sure sign that rain is coming? It's a popular piece of folk wisdom in rural areas where cow pastures dot the landscape, and it falls into a much broader collective of anecdotal weather-predictions. People have been doing their best to forecast the weather since long before modern types of meteorology came about, and while no weather forecast can be perfectly accurate, these older methods were a real hit-or-miss affair. Some adages, such as a red sunrise predicting storms on the way, have an actual scientific basis, but as far as bovines go, you probably shouldn't trust them for a forecast.

The idea that a herd of cows lying down together is a sure sign of rain is simply an old wives' tale, although several pseudoscientific explanations have been proposed. Some say that cows lie down when rain is incoming so that they can preserve a dry patch of grass. Others claim that cows' digestive systems are highly sensitive to changes in atmospheric pressure, and that they lie down in advance of rain to give their tummies a rest. Still others argue that cows lie down before rain to conserve body heat. These explanations may sound convincing at first, but they all hinge on the idea that cows can sense rain before it comes, which isn't backed by evidence. The real explanation behind this old adage is much simpler: It's probably a complete coincidence.

In truth, cows often do lie down before a rainstorm, but they also lie down on sunny days, foggy days, and in almost every kind of weather. Cows just spend a lot of time lying down, as much as 12 hours per day, which is why cattle farmers need to provide bedding materials in their barns. Cows require lots of rest, although they don't sleep in the same way humans do. Cows sleep in short intervals, and they only get around an hour of true REM sleep each day. They can only achieve REM sleep lying down, but they can rest on their feet too. That may be one reason that people read into cows lying down so much — they aren't lying down for the same reason we humans usually do — but cows have other good reasons to get off their feet.

If you see a herd of cows lying down in a pasture, they are most likely just resting or chewing their cud. Cud is semi-digested food that cows regurgitate into their mouths and chew again. It may sound gross from a human perspective, but for cows and other grazing animals, chewing cud is essential for getting every possible nutrient out of their incredibly fibrous diets. Cows spend about eight hours a day chewing cud, and if one cow lies down to do so, the others are likely to follow because they are herd animals that like to mimic each other's behavior.