Explained: The secret life of antlions

The Hindu

28-06-2025

The sun is up, the air is crisp and it is a glorious morning. You are an ant and you have woken up and left your nest and colony behind. As you walk by, enjoying this bright, beautiful day, with dreams clouded on nibbling a sugary treat waiting for you somewhere, you suddenly notice your legs giving away. You slip, arms flailing. You frantically use your tiny arms, as you try to grapple onto something and climb up. But it is too late. You keep slipping down a sandy, steep, slippery slope. The sand collapses and you lose your feet, and more sand falls onto you. It is like an avalanche. Only it is not snow, but heaps of sand. The fall is mighty, the incline doesn't help and before you know it, you have fallen- caught and trapped in the sneaky little pit trap laid out by an antlion. Oops! It's game over for you buddy! Sorry!
If you are an outdoorsy person, you would have sometimes noticed tiny, 3-inch wide conical pits on the ground. Seen where the soil is loose, these spiral, conical holes are created by a tiny, oval, and plump brown creature with a flattened head that protrudes forward. If you have been adventurous and went poking about in this pit, you would have seen a 'bug' scrambling in, throwing sand upon itself and trying to dig itself further deep inside the sandy pit. What many of you may not know is that this little creature is just the larval stage of the insect antlion. And once it moves into the adult stage, it will fly away- an insect you may dismiss off as a damselfly.
If we got you to read till here, let's dive into the secret, little, documented lives of these antlions.
What's an antlion?
A type of insect belonging to the family Myrmeleontidae (belonging to the order Neuroptera), the antlion is most familiar to you in its larval stage. That is, the creature that you accidentally find in these pits. 'The pit-making larval stage is only one stage in the antlion's life. This is a highly predatory stage, and one that most people would be familiar with. But not all antlions make these conical pits. Only a few species do. Some of the species will hide themselves behind fallen leaves on the floor to catch the prey. These are ambush predators,' says Dr. Bijoy C, Assistant Professor, Department of Zoology, Christ College, Irinjalakuda. Bijoy and his student Suryanarayanan T.B. figures among the very few scientists in India who research upon antlions.
There are four stages in the life of antlions. The first of course is the eggs which are laid on the ground. Once the larva (popularly called as antlion) is born out of this, it takes up residence under the soil pits in the sandy ground. It is here that the highly aggressive predatory behaviour of the antlion is observed. The inverted conical soil pit is crafted by the antlion by throwing off sand, as it moves in a backward motion. And here it lies in wait, for an unsuspecting ant to walk in. There are more than 2,000 species of antlions around the world. India is home to about 124 species (belonging to 35 genera) of antlions.
Conical pits
For antlions to make these pits, some conditions need to be satisfied, such as the presence of loose soil. It needn't necessarily be sand, but the soil cannot be tight and hard. Alternately, these pits cannot be made in regions that get too much sunshine or rain. As such the pits are created in regions that get plenty of shade and are positioned away from the possible onslaught of rain. They are some two inches deep and around three inches wide.
So how does the antlion make this pit?
The larva will move backwards, scooping up the soil, flicking and throwing it across, as it digs further and further, creating a spiral and a circular groove. It moves from the circumference to the centre, eventually making a round, conical pit. Once the pit is created, it will then settle itself underneath with widely opened jaws, buried in the sand, as it waits for its prey to tumble down. 'The larva produces an enzyme which digests the body parts and it will then suck the fluid out of its victim. There are reported instances of the antlion feeding on cockroaches and beetles. Once it feeds on its prey, it will then throw the pieces of the carcass outside,' says Bijoy.
Metamorphosis to the adult stage
'During its larval stage, the antlion's main focus is on feeding,' says Bijoy. 'The larval stage is the longest in terms of duration. In the next stage, it pupates. It will make a cocoon, which stays buried inside the soil. In this globular pupation stage, the cocoon is made with the silk it spins and fine soil particles. It will stay here for a few days, which may go up to a period of 40 days. Then it will grow wings and fly out, searching for a potential mate,' says Bijoy. The adults are sometimes called antlion lacewings.
'The adult resembles the damselflies. So people often confuse the adults for damselflies or dragon flies. But if you look closely, you can see that they are different. Their wings are very fragile, translucent and net-like. They have very prominent clavate antennae and their posture is also different. Once the larva becomes an adult, there are little references of any foraging. There are some references on the adults feeding on pollen, but it is still disputed. The key focus in the adult stage is procreation. The adults are nocturnal,' he adds.
An understudied species
Antlion species are so understudied that sometimes they have to be redescribed. In a recent study by Bijoy and Suryanarayanan, a taxonomic revision and re-examination of 21 species in Myrmeleon recorded from India was done. And their results show that only five valid species of Myrmeleon reside in India. The most common antlion species in India is Myrmeleon tenuipennis. 'The lives of antlions are perhaps the most understudied. Even in India, we have very few researchers studying about antlions. One of the pioneers was Dr. S.K. Gosh. We are yet to know more about these species. Only more research can throw light into this,' says Bijoy.