For those fascinated by the abstract universe of mathematics, David Gale's columns in The Mathematical Intelligencer have been a prime source of entertainment, and here his columns are collected for the first time in book form. Encouraged by the magazine's editor, Sheldon Axler, to write on whatever pleased him, Gale ranged far and wide across the field of mathematics, frequently returning to favorite themes: triangles, tilings, games and paradoxes, as well as the particular automaton that gives this collection its title, the automatic ant. Suitable for everyone having some familiarity with mathematical ideas.