tiny whirlpools in sand

We may have noticed these common holes in soft sandy patches and walked on.

Few might imagine that these tiny holes are actually the engineering effort of some young insects (antlion larvae), at work catching a little hard working engineer – an ant!

As ambush predators, catching prey is risky because food arrives unpredictably and, for those species that make traps, maintaining one is costly. The larvae therefore have low metabolic rates and can survive for long periods without food. They can take several years to complete their life-cycle; they mature faster with plentiful food, but can survive for many months without feeding.

~ wiki

Their full lifecycle (from wiki)

Was wondering about the rest of their story and if they’re still as voracious as an adult…

When the larva attains its maximum size, it pupates and undergoes metamorphosis. It makes a globular cocoon of sand or other local substrate stuck together with fine silk spun from a slender spinneret at the rear end of the body. The cocoon may be buried several centimetres deep in sand. After completing its transformation into an adult insect over the course of about one month, it emerges from the case, leaving the pupal integument behind, and works its way to the surface. After about twenty minutes, the adult’s wings are fully opened and it flies off in search of a mate.

The adult is considerably larger than the larva as antlions exhibit a great disparity in size between larva and adult. This is by virtue of the fact that the exoskeleton of the adult is extremely thin and flimsy, with an exceptionally low density. The adult typically lives for about 25 days, but some insects survive for as long as 45 days.

The adult insects are less well known, due to their relatively short lifespans compared to the larvae. Adults mostly fly at dusk or after dark, and may be mistakenly identified as dragonflies or damselflies; they are sometimes known as antlion lacewings.

~ wiki