We found a spot on the edge of the river where we could look out over the flowing water to watch swallows hunting acrobatically & sandpipers skitting along the shoreline.
We had been sitting there for a few minutes when we noticed a little hole in the ground next to where we were sitting. It was a small hole only a quarter of an inch in diameter. We wondered about the insects that make their variety of holes and casually speculated if there might be something in the hole.
We went on with our conversation but then after a few minutes we noticed that the previously vacant opening was now obscured by the face of an insect. We created a bit of vibration in our curiosity & it ducked back into the depths of the hole.
We watched & waited until half a minute later the creature had emerged to the mouth of the tunnel again. It looked like it was just waiting for something to come along.
My friend grabbed a piece of grass and started slowly moving it in towards the hold so we could see what would happen. Would the insect attack the grass?
She had to move the grass very slowly because the slightest movement from overhead would send the insect diving back into its hole. After a couple failed attempts that sent it racing into the depths of the earth we got the grass within inches of the hole.
The tension was building as she lowered it more & more, Closer & closer. Just when we thought it couldn't get any closer the insect lunged out of the hole & grabbed the grass but upon realizing that it wasn't an agreeable target, retreated back down into the earth. It happened really fast.
After a few times of seeing the pattern repeat we were confident that we had learned it's hunting strategy and we decided to leave the poor critter alone.
When we got back from our walk we looked it up in an insect track & sign book. We found the exact behavior described in the book & discovered that our mystery insect was the larvae of a tiger beetle.
It was so funny to see the same observations we had just made written almost word for word in the field guide as though a researcher somewhere had once enacted the same experiment we just performed on the edge of the Tolt river... The crazy things we do for science and entertainment.