Rabbits in the Polytunnel

The blasted things don't tunnel anywhere else in our garden, in fact evidence of them is non-existent outside perhaps owing to our 3 cats being on patrol.  HOWEVER, they (assuming it's rabbits) have decided that the polytunnel is a lovely environment for burrowing.  Currently there's nothing planted in there and now I'm loathe to sow anything lest it gets nibbled up - sigh. Any ideas how to stop them - humanely?

Dig down outside the tunnel ... all around... a deep trench with fencing dug in.
OR
Lay metal mesh on each inch of the floor and build raised beds over this
OR
Keep a cat or small dog inside the tunnel at night?

Basically anything you would use to keep rabbits in would keep them out. Bit of effort though. Not as much as planting for a rabbit hotel though.... 

Chelle

oh i bet they DO love it..i can just see peter hanging up his little coat in there to dry after a rain..

good luck with that..i'm sure you'll figure out how to keep them out..or..you can still eat them for a little while.

I would say plant something in there they would like to eat, then build another polytunnel with metal mesh barriers and use it they way you planned to use the first one!

I love rabs.

we fixed the problem inadvertently.

our piglets had to spend their first night in there and after that, no more visits.  brilliant 

pigs are smarter than anyone thinks!