Naturespeak A naturalist's view of the world

September 2, 2010

Crater Makers

Filed under: Uncategorized — wykes @ 9:01 pm

One of my favorite movie scenes of all time is the sequence that takes place over the giant Sarlacc pit in which Luke, Leah, Chewbacca, and the gang avoid certain death in the open jaws gaping at the bottom of the pit. I am, for those of you not versed in classic science fiction, referring to the Star Wars series and the movie Return of the Jedi. The scene takes place on the desert planet of Tatooine “a long time ago in a galaxy far far away.” Specifically the creature is in the great pit of Carkoon in the northern Dune Sea, but let’s not get too picky here. The creature depends upon wandering creatures and/or villains to bumble into the pit and slide down the sandy slope to their doom.

Fortunately, or unfortunately – depending how you view such things – there are real life Sarlaccs right here on earth in a place not so far away. They are the larval form of an insect called the Ant Lion. Although only ¼ inch long, these un-worldly looking beasts create sand craters in order to trap passing insects such as, well, ants.

Most nature type folks are aware of Ant Lions, but they are always worth a closer look. I fondly remember spending countless hours, as a kid, tossing ants into the neighborhood ant lion pits just to watch them die. This activity was much more satisfying than cooking ants with a magnifying lens. It’s been a very long time since I’ve sacrificed an ant at the altar of craterdeath, so I decided to try it again. The results were surprisingly tame this time around. Perhaps youthful imagination provided the screams of agony and the roar of beastly madness, because each event was over in a silent flash.

The larvae of the antlion looks like a hairy wart coupled with a pair of nasty hedge-clippers (see above). Arguably, it is one of the ugliest creatures on earth with the possible exception of Dog the Bounty Hunter. It is a hunchback thing with (proportionally) enormous toothed jaws. They construct their sand traps through a series of backward spiraling movements. The sand is flipped out at regular intervals with a jerk of the head. Eventually an inverse cone is created in which the sides are barely stable (something called the angle of repose). In all, the structure varies in size from one to two inches across. The larva positions itself at the bottom with only a portion of the head and jaws exposed. There it waits with infinite patience.

When an insect does tumble in, or one is thrown in by a sadistic naturalist, it attempts to scramble up but the sides collapse inward with each struggle. The ant lion strategically flips a load of sand at the prey to hasten its fall (You can watch the sequence here – the first part in regular time and the second in super slow motion.). Once in the grip of the lion jaws, the victim is paralyzed and its innards are summarily sucked out. This is why there is very little action at the Sarlacc pit after the initial struggle. Like a used box drink, the empty carcass is later flipped out of the crater.

It is worth noting that the antlion has no anus with which it can poo out the undigested remains of its prey. They essentially store up all this youthful crap and wait until becoming an adult to void it. This goes a long way to explain why the insect has such a big butt.

It can take up to three years for an ant lion larva to grow up (and eventually go to the bathroom). As an accidental predator it takes that long to ingest enough prey juice and gain enough weight to take life to the next stage. The adult antlion, by the way, is a very wimpy looking creature indeed. It is the Dr. Jekyll to the Mr. Hyde.  Think of an anemic damselfly with a set of ridiculous looking antennae and you have a good visual image of the adult. The name “antlion” is definitely all about the larva. It is the vicious larva that was depicted on ancient Mimbres Indian pottery and this is the beast that captures our current imagination.

3 Comments »

  1. Great stuff. Grabs the imagination. I don’t recall seeing antlions as a kid, but I know I would have been fascinated.

    Outstanding writing as usual.

    Comment by jim — September 3, 2010 @ 8:38 am

  2. Wow. On so many levels, this was a great piece. I need to take a closer look at Mimbres pottery now.

    Comment by Ellen — September 3, 2010 @ 2:18 pm

  3. […] Crater Makers (also see: The Mighty Ant-Lion) […]

    Pingback by Quick Links | A Blog Around The Clock — September 5, 2010 @ 1:45 pm

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