RAINING CATS AND DOGS
During the 16th century, and indeed before and for some time after, each home had a thatched roof. It was a comfortable place for animals of all sorts to live. When it rained heavily, the animals would fall to the ground. It is doubtful that dogs could climb up to the roof. Perhaps cats could. Nevertheless, the expression "raining cats and dogs" came about because of the animals in the thatch fell to the ground during heavy rainstorms.
