A poison frog about the size and color of a mint chocolate bonbon is quietly upending what we thought we knew about how frogs think. Native to tropical rainforests of central and South America, the land-adapted species Dendrobates auratus eschews rivers and lakes entirely, instead laying its eggs on the forest floor. When the eggs hatch, the frog piggybacks its tadpoles up into trees, placing them in water accumulated within tree holes and bromeliads.

To find, remember, and navigate among egg nests and tadpole nurseries in such a complex, changeable landscape requires a brain that can make and revise a mental map of its surroundings. Many mammals and birds form such maps. And now, new research in the