Hello. Im new here. Great site!

My Runner beans have been growing nicely and are now flowering. The flowers fall and leave a tiny runner bean. Its there for a day or so and then dissapears! Something is eating the tiny beans. The leaves are not being eaten. What could it be and what could I do about it? I do have alot of ants running up and down the stems but they dont seem to be eating anything, just playing around. could it be the ants?

Im also growing greenhurst peas and dwarf french beans which are almost ready to start cropping. Whatever is eating my runners are just sticking to the runners and leaving the others alone.

Any help, opinions, advise would be greatly appreciated. Thank you!