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Isaac Newton invented the cat flap. Newton was experimenting in a pitch-black room. Spithead, one of his cats, kept opening the door and wrecking his experiment. The cat flap kept both Newton and Spithead happy.

Since cats are so good at hiding illness, even a single instance of a symptom should be taken very seriously.

An adult lion's roar can be heard up to five miles (eight kilometers) away.