Can't figure out what's eating my chard
I bought a house this summer and put in a raised bed a couple of weeks ago. I planted some chard starts, just to have SOMETHING going in my garden before winter. They were doing fine here in California; there are no insects around that I can see except maybe some ants. But something is eating one leaf at a time. It doesn't look like the ants are doing it.
I've been out at night with a flashlight and never see anything; haven't seen flying bugs around. What would be eating chard this time of year? My only other experience was spinach leaf miners when I lived in Washington state.
I have snail bait and diatomaceous earth around the plants to no avail.
How can I deal with this when I don't know what I've got? Any help will be appreciated.