Stoats gets through gaps of less than 5cm! The rats will dig the tunnels for them...
After a stoat got into our fox proof run a few years ago I bought a load of mesh off ebay and double lined the whole run. Not cheap but so worth it.
Chicken wire will only keep the birds locked in a convenient space with no escape for the passing predators to take at their leisure. I wish it wasn't called chicken wire, pea netting would be a better name for it.
Your thoughts on battery operated energisers, please, people, as I'm not impressed by the Gardman we used for the pigs, the cables come off too easily when curious rabbits take a nighttime nibble. I'm going to try the method of penning landscape fabric under it to avoid earthing. Whilst on the subject: which brand of netting do you (now / no longer) use, please?