Cold water and hot water sound different when they're being poured, because heat changes the viscosity of the water. The middle finger nail grows the fastest. The book Green Eggs and Ham was written by Dr. Seuss as part of a bet with a publisher that he couldn't write a book only 50 words. (Seuss won.) Pope Gregory IX was apparently a dog person, because he tried to exterminate all cats from Europe. Caterpillars liquefy in their cocoons before turning into butterflies. The Indian/Western Taipan is the world's deadliest snake. Its bite contains enough venom to take out 100 adult humans in less than a half hour.