Ant Invasion

I have a raised bed off on its own. The bed is quite shallow, but it is a hugel beet, separated from the soil with 1/2" hardware cloth (to keep gophers out. The year before last it became totally overrun with Bermuda grass. Last spring my son and I removed the bed, repaired the bed, the Bermuda grass took prisoners. removed as much of the weeds I could.  The last corner was very hard to clear because there was so many ants. They were only the little black ants, but there were so many I would become covered in ants and they do bite. I dumped a bunch of diatomaceous earth, and left it for quite a while. I did finish the weeding, and was able to put the bed back. I didn't end up using it until this fall. Again I had to put a bunch of DE before I could prepare and plant the bed. There's been a lot of ants, but not so many I couldn't work in the bed. Until today. the fava beans are covered in ants. I didn't see any aphids, but there were so many ants, and they were getting on me and biting, so I couldn't investigate very well.
So what do I do?  With the exception of this bed, I have never had to bother with ants. But I can't even water this bed without having ants all over me. Should I put a bunch of DE on the soil and plants, should I make up some borax and sugar and put it by that bed? Do both?  What would you do?

ants will be coming to help break down the organic matter in a hugel. If theyre not damaging your plants it's one thing, but if they are I'd consider harrassing them. Find their hole and flood it and see if they move. Stir up the dirt nearby and see if they decide to go somewhere else. Keep in mind, the next place they go might be even worse!
(with leafcutter ants that destroy my plants, I'll find their nest and dump boiling water on it, or soapy water from washing dishes.)

Ants don't like vinegar and if you have alkaline soil vinegar will fizz.  It will also lower the PH of alkaline soil,

Vinegar kills ants.

Please let us know what was effective for you. While we have ants up here in Maine, ... they are not very tenacious. We stir up the nest a bit and they don't come back.

The ants are covering the fava Bean flowers. I haven't seen any damage to the plant. Honestly I would leave them alone, if they would leave me alone. My first thought when I saw them was I must have aphids.  I didn't see any aphids, but just getting close to the bed I'm crawling with ants, so I haven't gotten a very close look.

Fava beans have extrafloral nectaries on the stems and leaf bases, the ants are there for the nectar not because of aphids. It's actually not a bad deal for the plant since the ants tend to chase off anything that might actually cause damage. I'd leave them to it honestly, they'll move on once the beans finish flowering.

Thank you all, there's lots to think about here.  I think I will spray vinegar around the outside of the bed, and leave the bed alone. I just need to be able to water, and tend to the veggies there.