Save my Fava Beans!

I'm growing fava beans in a container on a second-floor balcony.

For a while I'd been seeing one or two ants in them, but I'd never heard of ants being a serious garden pest, so I didn't worry. But this morning they were all over!

Even worse, they seem to be eating from these little brown spots that have appeared right at the base of many of the flowers and branches.

Questions:

• What do these brown spots signify? (I assume it must be something, because they're appearing in very specfic locations on the plant.)
• Are the ants the cause of this problem or just a symptom?
• Will getting rid of the ants solve the problem?
• How do you get rid of ants in a container garden?
• If getting rid of the ants won't be enough, what else do I do?
• Should I stop anticipating eating these favas, or is this probably fixable?