Hello and welcome!
I have seen tunnels here or there on the property but once the Shepherd starts digging seems like they clear out. If i were you i would investigate mole traps. Ultrasonic repellents don't do anything but drain your pockets imo. Let us know what happens. Love daffodils!

It's the smell of sulfur from the garlic as well as smell from daffodils that repels them. Great thing about daffodils are that they're buried 6in under and naturalize every year. And they better protect the tree roots, IMHO. Garlic can be planted as little as 2in in soil but needs to be forked up in June, then allow to air dry & cure for 2-3 weeks prior to use. Like lazygardener.....I'm even twice as lazy!Daffodils? Garlic? These repel moles? Tell me more!

Are they moles, or voles? I can catch voles with snap traps. I caught 5 voles with a single chocolate chip/peanut butter. First Bubba, then Peggy Sue, then Johnny, then Linda Lou, then.... Voles aren't the brightest crayon in the box. Every time I caught one, I'd toss the body into the bushes, then re-set the trap in exactly the same spot, right in front of an active hole. There'd be an other cousin or uncle in the trap the next morning.
Garlic and daffodils are supposed to repel voles, and I'm guessing they do the same with mice. I have them planted around all of my fruit trees.
It's moles. The tell-tale brown lines of dirt as well the fresh mounds of dirt. Right now the ground is thankfully frozen. Was your snap trap like this:
