ants and spuds

Ants don't eat potatoes, nor do they bother with the plants. If anything, they've found a food source in the immediate area which they like and it sounds like your potato spot is their idea of home. Sprinkle corn meal (not flour) around the area to drive them off. They detest this and will move away.

One year when growing spuds through plastic weed suppressant sheets, ants had colonised the bed under the plastic.  I was none to happy when I came to harvest the potatoes but I did notice this crop had much fewer slug holes compared to a nearby bed that had been planted up in the traditional way.  So not such a disaster after all 

Ants don't destroy or attack vegetables themselves. But, they will hang around carrots while carrot flies do the damage and the ants will then scavenge what they can. The carrots will enjoy the softer soil the ants create while tunneling but you don't want to encourage the ants to stay in your raised bed. Do a soil drench with insecticidal soap and whatever other methods you can to get them to move on. Hoeing the area will help as ants hate disturbance in their nest areas.