You’ve probably heard the expression “it’s raining cats and dogs” and know it isn’t a literal saying. Cats and dogs aren’t really raining down from the sky. It just means it’s raining really hard.
While it can’t actually rain cats and dogs, it's not for the reason you might think. It actually can — and does — rain animals, but mostly aquatic creatures. This is why it can’t rain cats and dogs, but it can rain fish and frogs.
Animals raining down from the sky is definitely not a common occurrence, but it does happen on rare occasions. When it does, it’s a real headlining event. Like in December 2021, when fish rained down from the sky in Texarkana, Texas. It was reported on by news outlets from across the country and even the world.
Words to Know
Aquatic: Any plant or animal that uses water as its primary habitat for at least a portion of its life cycle.
Depictions: Representations of something or someone in words or images.
Mythology: Folklore consisting of stories that play an important role in society.
Phenomenon: A fact or situation that is observed to exist or happen but whose cause or explanation is in question.
Prominently: Having an important role or to a great extent.
Theories: Ideas intended to explain something that isn’t known for certain.
The phenomenon of animal rain isn’t well understood, but it’s been reported for centuries. When it does occur, it’s typically associated with waterspouts or updrafts. These develop over water, which is why animal rain mainly involves aquatic animals.
Waterspouts develop when violent storms move over large bodies of water. These whirlwind clouds then dip into the water, pulling up water and small objects like pebbles and sometimes small animals like fish. Similarly, strong updrafts can sweep up small animals. Because of the strength of updrafts, they can sweep up larger animals, such as frogs, snakes, birds and bats, than waterspouts typically do.
When these waterspouts and updrafts move over land, they lose some of their energy. That’s when animal rain can occur. Heavier objects will fall first, and the lightest objects — normally raindrops — fall last. This explains why when it rains animals it is typically only one kind of animal. The waterspout or updraft will first drop its heaviest objects, typically frogs or fish in the case of animal rain, then go on to drop anything lighter before finally letting raindrops fall to the surface.
So if it has never really rained cats and dogs, why do we say “it’s raining cats and dogs” in reference to a heavy downpours? No one really knows for sure, but there are a few theories. The oldest documented use of the phrase is a 1651 collection of poems by Henry Vaughan that includes the phrase “dogs and cats rained in shower.” In 1738, author Jonathon Swift wrote, “I know Sir John will go, though he was sure it would rain cats and dogs.”
One theory about the origin of the phrase links it to 17th-century London, England. At that time, the city was filthy, and the streets were filled with stray animals. When the streets flooded after heavy rains, it’s likely dead animals, including cats and dogs, would be seen floating down the streets. This could have given people the impression that these animals had rained down from the sky.
Another theory about the phrase’s origins dates it much further back in history, to English and Norse mythology. Witches feature prominently in English mythology, with cats heavily associated with them. And in Norse mythology, Odin travels in storms with packs of wolves and dogs. These depictions are thought to have possibly given rise to the now common phrase.
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