I guess that they are eating the bean seeds? If this is the case then you need to mask the scent of the seeds. You can try: chili flakes, naphthalene (crushed moth balls), or Obas Oil dripped on small pieces of kitchen paper. You would need to re-sow some rows with any of these at stations in the row. Years ago gardeners would soak the seeds in paraffin or red lead powder but I wouldn't recommend this.

If you are actually seeing rats running around then you have a serious infestation and you need to contact your local council environmental health department - before your neighbours do. And it would be a good idea to stop feeding them, which is what you are doing by growing crops that they're attracted to.

Refer to my previous answer to you on Jan 20. Also, you may have a neighbor that has a shed or some other structure or pile of debris that is providing an excellent breeding area for rats. Do you live in a urban or rural area? If urban, you have a very serious problem which requires professional help. I mention professional help since it seems like warfarin baits might have to be utilized........I dont like the stuff but this is war.

Since the rise in decking as a sitting out area rats have become much more of a problem. the decking provides excellent shelter for them. Do you or your neighbours have any?
I'm rural and although we got the odd one in from the fields they were never really a problem. that is until our neighbours decked 1/2 of their back garden. After 2 years they had to pull it up and are considering redoing it now with rat guard netting at the ground level.