woodlands vibrations

So we set aside a corner of our property (the whole propety is 13 acres) to leave wild for observation. We set about making a trail through it and putting a small gazebo in the center for an observation post (cedar logs topped with a feed bin roof). While making the trail, there were a few spots that I put my foot in that vibrated. Because it was so different, it made me wonder about it. Has anyone ever experienced this? What would cause the vibrations? At first, I was thinking underground yellow jacket nest, which caused me a bit of a fright since I have accidentally dug one up.

The vibrations could be caused by a number of different things.

Did you take the time to really observe the area around your foot that felt the vibrations?
If it was indeed a yellow jacket nest you probably would have had scouts come out just from the pressure of your foot step.
The thing to do is observe and make notes, this will put you closer to the cause of the vibrations and if they aren't present all the time, it would most likely mean it is an anomaly.

On Asnikiye heca we have two places where there are convergent lay lines, these places vibrate all the time, at certain times (usually around the full moon and the new moon) you can see the plants moving because of the vibrations.
It was pretty interesting when I first found these special places on our land, observation and then checking lay line charts revealed what was happening.

We have a tree that vibrates, it is caused by a huge honey bee nest in the tree. I try to avoid that area since a sting could kill me in an hour if I don't get to one of my epi pens quickly.