Why are Some Tree Frogs so Colourful?

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About 500 species of frogs spend their lives on tree tops. Some South American tree frogs are very brightly coloured to warn predators that they are extremely poisonous to eat. All the amphibians have mucous glands in their skin to keep themselves moist. In some frogs, these glands also produce a poison so deadly that it can paralyze a bird or monkey instantly. South American Indians use secretions from golden arrow-poison frogs to poison the tips of their hunting arrows.

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