My beans get snipped every year. Birds? Rabbits? They usually re-leaf in short order. This year I planted my beans in raised beds and there was much less damage which makes me think that bunnies are the culprit.

I blame the rabbits.

A picture can help a great deal.

Slugs do not chomp off, they leave often some the leaves uneaten. It is easy to detect slugs: Go out at night with flash light and check patiently. I have heard rabbits love beans.

Maybe it's neighborhood pets or animals.

My cat, when left outside at night, will either hunt for food or nibble some fresh leaves from the garden. I woke up this weekend to find all of my sunflowers stripped of leaves (and yet the stem remained). Bruce promptly darted out of the garden.

Unless your fence is very good, I'll guess it's a rabbit (young ones can squeeze through a very small hole, and they look long and hard to find one).

LOL The only fence I have is... a 16-ft cedar hedge, but we do live across the street from a large wooded area and I HAVE seen deer, but they've not crossed the street because the neighbour's garden is bigger than mine and it's right next to the river so...

I HAVE gone out at night w/flashlight, as I sometimes do to check on my hostas, but have not seen any slugs. The beds are raised beds as well.

So I'll go with your bunny theory, although I and my neighbours have never seen any, and there are plenty of cats out at night. Thanks so much for your input.
I'm glad to hear the plants will survive despite the early chomping from da monstah from da black lagoon... :D
Happy gardening!