Ant Lion pits

Technically speaking, the term Ant Lion applies to the immature or larval stages of the members of this family. Ant Lion larvae are predatory while the adult stage feeds on nectar and pollen. Larvae are voracious predator of ants and other small insects that become entrapped in the conical pits constructed by Ant Lion larvae.
Ant Lion larvae are sit-and-wait predators that construct sand pits with the shape of an inverted cone or funnel.
The pits are found in dry places that are sheltered from exposure to high winds and intense sunlight. These pits are usually 1½ to 2 inches in diameter and about the same depth. (Some Ant Lion species also hide under bits of debris or wood and attack passing insects.)

The Ant Lion larva waits at the bottom of its pit for an ant or other insect to slip on the loose sand and fall in. The unsuspecting prey falls to the center of the pit and into the waiting jaws of the Ant Lion larva. Prey will oftentimes attempt to scramble up the steeply inclined walls of the pit. Such efforts to escape are typically to no avail. An Ant Lion larva quickly thwarts such escape attempts by rapidly flicking showers of loose sand, which further destabilizes the wall of a pit and thereby draws the prey downwards.

Ant Lion larvae (Myrmeleon sp.) are also known as doodlebugs. This nickname is apparently in reference to the randomly winding and spiraling trails that young larvae make in the sand while seeking a suitable location to construct its larval home. The trails look like someone has been idly doodling in the sand! The larvae’s home in the sand is also a novel insect trap known as a pit.