Insects can stop dead without falling over because three legs are always on the ground while moving.

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"Extra legs do not help an animal to move faster. The millipede is slow for all its legs - in fact, if it hurries it is liable to trip over its own feet! Insects have six legs and tend to have three of them on land at any given moment while moving; they can therefore stop dead without falling over." (Foy and Oxford Scientific Films 1982:46)

Book
The grand design: Form and colour in animalsBLA Publishing Limited for J.M.Dent & Sons Ltd, Aldine House, LondonAugust 22, 1983
Sally Foy

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Living System/s