Antlion

The larvae of some antlion species hide under bits of debris or wood and attack passing insects.
In sandy regions, some species dig a shallow cone-shaped pit and wait at the bottom for an ant or other insect to slip on the loose sand and fall in, only to be immediately devoured (Arnett 1985, 260). These pit-digging antlions are called "doodlebugs" in the United States because of the designs they make in the sand. As a doodlebug seeks an ideal location to dig its pit, it leaves meandering trails that resemble the random "doodles" of a preoccupied artist. When it finally finds the right place to dig, the doodlebug "draws" a series of concentric spirals, each deeper than the last, until the pit is excavated.