What's eating my plants? *sniff sniff*

Most of the plants are doing well, but lately (as in past week or so), I have noticed that something is eating my sunflower and the runner bean vine. There are random holes and toothy edges in the leaves. At first I thought they were kind of dry, but they are getting adequate water and growing just fine... except for the disappearing portions of leaves. See pics:

Runner Bean







Runner Bean... different leaf, same problem







The whole runner bean plant







Mammoth sunflower. This is the most damaged leaf, but there are others. In addition, there was another one that I cut off that was pretty much eaten all the way to the central vein in a toothy, zig zag sort of pattern.






There are also mushrooms growing in the runner bean pot. Could that be significant? I've been picking them out because I think they're just ugly, but perhaps they could be bad for other reasons?

Anyway, the rest of the garden is doing well. We've taken to putting the pots up on platforms when we're not entertaining to ensure they get enough sun. It doesn't look so pretty, but it works :) Here are the latest pics: