What's drilling my cabbages?

This is Drago a spring cabbage but I am having to cut them now as they have been heavily drilled by something.

I haven't seen caterpillars in the netted cage and there isn't the telltale caterpillar faeces between the leaves. Slugs? but I thought they wouldn't stay long enough to drill holes quite this deep.

Voles do that to my cabbages ---Golden Acres. Have to cut them as soon as they are ready to eat so that they stay intact.

Luckily they don't seem to like red cabbage 

I have had some similar holes and the culprits were still there, big fat slugs.

I was just wondering what sort of netting you use to keep cattaspillars and butterflies out.  I have some spring cabbages and caulis that I am intending to plant out.

Sweet Pea, I use scaffolding netting, it's cheap and can be used year after year.  Your cabbages etc will be susceptible to pigeon damage this time of year rather than caterpillars etc.

I used debris netting this year - cheaper than fine mesh insect netting.

Check out my diary page to see debris netting in action.
It is over water pipe hoops, make sure you get the wide netting, as you need a fair height to get over the top of your brassicas.

Mel