Sometimes an animal, bird or rodent, will see the bean skin on the cotyledons and grab it. Sounds like this might be what's happening. I have a similar problem with my free range chickens when I plant things outside of my fenced garden. I find that I can place a barrier, like some chicken wire over the plant, until it's established a bit. That helps. Another thing to try would be to get some large plastic cups and cut out their bottoms. Stick them over each little seedling. Perhaps if the varmint has to reach into the cup to get them, that'll deter him.

George
Tahlequah, OK

George that's an excellent idea, I'm going to file that one away and use next year. My beans are starting to climb their poles now so it looks like they're over the hump. It's been quite the spring here in the PNW, WET.

Annette