@trib @jpm @hacks4pancakes it's mildly gross and might get you done for exposure if the burrow locations are visible to neighbours or the public, but you could try pissing around the entrances. It's worked well for me :-)

Or you could take Banjo's advice and put in a swinging gate so they can come and go without damaging stuff. Especially if you don't mind having them elsewhere on your property. Make the gate heavy so that other animals will be unable to get through.

"The strongest creature for his size
But least equipped for combat
That dwells beneath Australian skies
Is Weary Will the Wombat.

He digs his homestead underground,
He's neither shrewd nor clever;
For kangaroos can leap and bound
But wombats dig forever.

The boundary rider's netting fence
Excites his irritation;
It is to his untutored sense
His pet abomination.

And when to pass it he desires,
Upon his task he'll centre
And dig a hole beneath the wires
Through which the dingoes enter.

And when to block the hole they strain
With logs and stones and rubble,
Bill Wombat digs it out again
Without the slightest trouble.

The boundary rider bows to fate,
Admits he's made a blunder
And rigs a little swinging gate
To let Bill Wombat under.

So most contentedly he goes
Between his haunt and burrow:
He does the only thing he knows,
And does it very thorough."