To answer this question we need to find out why cats seem not to be scared by thunder, equally as ominous and dramatic as lightning. A cat's hearing is massivley more accurate and sensitive than ours. A domestic cat will be used to loud sounds: refuse collection lorries, loud music or children rushing downstairs. A wild cat will probably know that thunder cannot harm them, like most sounds. However they may know of another cat (relative or opposing pride[?] of cats) that has been killed by lightning. This may still remain in domestic cats. Anyway, a huge flash of intense light setting fire to trees is far more fear-inducing than a loud rumble of thunder. Cats might be cautious of very loud cracks of thunder in a very heavy storm. Either way cats and thunderstorms aren't a good combination.
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