'Who's been eating my leaves.....?'

moths maybe,, caterpillers, look under leaves Dan, i had lots of little catterpillers under some leaves

Will it damage it overall or is it just part and parcel?

I will go take a look in a minute.

dont think so, do these shed leaves in winter, if so it doesnt matter,if not then it just looks untidy till whatever it is goes walkies, my clematis is the same and full of holes in leaves, its apparently moths

I think the Meerkat family have been at it, as they anxiously await their new names :)