The digging around and under the traps is common in my experience with moles. It is critical to set your trap jaws centered in the run as best you can. If not, they will see them as a obstruction of sorts and avoid the blockage as they would any resistance that appears to them to be too much of an obstacle for them to work with.
Bedding your traps better into the dirt by compressing them down to almost ground level and centering the jaws will help you to avoid this.
I use a dandelion tool for bedding and placing the traps back into the runs. I set a couple of ways depending upon the conditions and the moles reaction to the traps.
To make it a bit easier to avoid this problem I incision a U shaped piece of sod to the depth of the bottom of the run about 8"-10" long and about 4" back on each end centered over the run. Loosen all three cut sides with your sod cutting tool to release the roots but keeping the cut sod in one piece the best you can. Then fold the sod back away from you and stake it down thru the center mass with your wire flag end to hold it out of the way while you work bedding your traps.
The Depth of your cut should be the depth to the tunnel bottom.A little deeper is better but too shallow isnt as good.I have built what I call a tunnel spreader tool. This tool pushes open the face opening of the runs to allow me to insert the traps more easily because the tunnels are a bit smaller then the jaw width of the traps.The jaws will hang up at times on roots, dirt,rocks etc. in the tunnel. The spreader just goes back in to the run the length of the trap. This allows much easier placement of the trap.
Opening the runs in this manner will give you an open look at the tunnel direction and depth. Center your traps with the jaws right up against the face of the exposed tunnel hole on each end. Press down with your dandelion tool tip and fingers. Pinch the soft dirt between your finger and thumb against the spring end of the trap to stabilize the trap better so it wont be pushed or rocked too easily when the mole contacts the push trigger.This practice will give you consistent good catches providing for a fast dispatch.
Set the opposite run trap the same way. I set my traps so each trap tether can be anchored with one wire flag.Occasionally I need two flags if the tethers arent close enough to do this.If you have cut your sod out the right size and this will take a few practice runs to get it right, you will be able to see the imprint of part of the mole tunnel in your cut out sod.
Before folding the sod back over to cover the run, I use the handle of my dandelion tool or a piece of cut broom handle or 1" piece of PVC pipe I carry about 8-10 inches long to press and squeeze it into the top part of the mole tunnel to re establish the form of the tunnel. This will allow the traps to function well once covered over and the tunnel will appear to be undisturbed to the mole when it comes thru once again..
It is best to minimize most of the surface air flow into run from the top of the run where you cut the sod open and minimize penetrating light because the mole will react to this and most likely plug the openings. Just pinch some dirt or sod around the needed open incision areas the best you can.
It is critical to re establish the folded back piece of sod into position as it was hinged back when you set the traps initially. Just press and fit the sod back to the ground level as it was prior to your cut out. Make sure you have the tunnel halves aligned as best you can. This is really an easy operation once you have done it a few times. This system makes for easy trap checking each time also.
Many times when I set up jobs some runs arent well rooted with grass and the tunnel surface run is dry dirt and it will break up and collapse when you cut the run open. To remedy this I just go some where to the lawn edge and cut out a well rooted piece of sod that will hold its shape and is moist.I just cut the sod size that I need to adequately cover the open cut out area of my run.
This works very nicely and makes trap checking easy. I simply re construct/replace the top of the run with a cut out sod piece just as it was prior to your cutting into the run. Compress the shape and proper direction of your tunnel run into the transplanted sod root area prior to placing it onto the open tunnel area.It is now just business as usual to the mole
When you pull your traps out and the job is complete just step down the cut sod and it will root very quickly in a couple of weeks. Its best you dont cut out the sod completely when doing your sod incision for trap setting for dig around mole activity.
I have done both methods using the 4 side cut out where you are removing the cut out sod plug to check your traps and the U cut out system utilizing the folded back sod method when experienceing the dig under and around situations by a mole. The folded back sod method will catch that mole on your next check.It allows a good trap bedding system and precise jaw placement with minimal disturbance to the mole tunnel.
I have also set another set of traps in the new established go around or under tunnel right by the mudded up traps that were intially set also and caught the mole as well. But I prefer to dig back into a virgin part of the run about 6 inches on each end and re set with the U sod cut method.
Good luck.
