Burrowing in potato bed

Nearly every morning for over 2 weeks I've been finding an approx. 30mm dia. steep hole burrowed down into the soil near the base of one of my potato plants, which I then fill in and firm down.

Whatever is making it returns overnight and digs again. It's always the same position and same plant, never gets as far down as the tuber (it's deep) and happened when covered with fleece. Too small a hole for a rat.

Whatever it is must be obsessed or insane. Have wondered about placing a small piece of fine mesh across where it digs, which is in precisely the same location every time, but will it then move on to another plant?

 

that looks like squirrels

 

I use a bar of soap and a old cheese grater works a treat sprinkled on the area

 

Maybe there's some smelly nuts buried there?

 

Foxes dig around mine every night.

 

Just noticed quite a bit of damage, onion bent over, leaves off toms etc.

I think the cubs are turning my plot into their play ground.

 

Voles???
Sometimes when i dig up our spuds i usally find a toad in one of the row of spuds, nice and damp for them

 

Right size hole, but I haven't known them dig up spuds before, only rats, and no idea why night after night it would burrow down about 5 - 6", not reach anything, return the next nigh, find the hole filled in and dig down to the same depth again and again and again. It must be a nutter - oh, back to squirrels again.

After ducks?

 

Probably looking for worms.

 

Fish blood and bone smell attracting the vermin?

 

There is FB&B + potato fertlizer on all 36 potatoes, but whatever it is burrowing, it's only interested in the one plant.