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The tiny black head is retracted here, and only visible as a "point" (looking like a sand-grain on the right-end).

Note also that Vermileo larvae have two sets of (somewhat inconspicuous) transverse "combs"...i.e. stiff rows of bristles (barely visible in the photo above) located dorsally about one-sixth the way from the tip of the abdomen, and ventrally about one-quarter. These bristle-combs help anchor the larva in the sand while it struggles to subdue prey.

Also, there's a single eversible/retractible "pseudo-pod" (i.e. a small "false-foot" protuberance) which is located medially on the ventral side on the larva about one-sixth the body length back from the head that is used to help grasp prey. The pseudo-pod is not clearly discernible in my photos here (it's largely obscured or retracted), but it is in the post below:

   

Both the stiff-haired combs and the (slightly retracted) pseudo-pod are also visible in Graham's post below:

   

This illustrative YouTube video shows a Vermileo writhing in its pit while capturing an ant.