We always called these doodle bugs when we were kids. If you take a small piece of grass and tickle the sand on the sides of the cone shaped hole, like a bug trying to climb out, it will throw sand up the sides to make "the bug" fall back down. They were always fun to play with. I hate to say it but I would occasionally throw an ant in just to watch it get pulled under. That was an odd place for you to find this though.
we have these! by: Anonymous
just came across this bug in Ashburn, Georgia. they dig a hole in the dirt/sand and locate themselves at the bottom of said hole. only pinscers showing. when an unknowing bug falls into their trap they SNAP with pincers and are very agressive about doing so!
Antlion larva or Dootlebug by: Moni
Richard
Glad you found out what it was...they are neat to watch in the sandy soils.
Thanks
Found it! by: Richard
Ah! I spoke with someone at a local university and they identified it as an antlion larva.
I guess it's constant backwards motion was its attempt to burrow into sand.