In article , gjclayton.6879dc7
@gardenbanter.co.uk says...

Thanks for all of your responses.

As for the outdoor plants: Swiss Chard, Beans etc... They have been
eaten by something which isn't leaving any signs except for the holes.
There are no trails, or sightings of any beasties except for the holes.
As I mentioned there are a lot of woodlouse wandering around, the odd
earwig, apart from that I can't see anything. Its not a major issue as I
think that they are growing fine regardless.
Do you think that this will impede the growth?

Is this what you are talking about?

http://www.hort.purdue.edu/rhodcv/hort410/8001.jpg

If so, it's flea beetle damage... and for the most part you won't see
them. They're tiny and quick.

We've had a lot of damage from these suckers over the years. The little
buggers here like chard, spinach and beets over everything else.