Ive grown potatoes for years, however, this year I decided to try two early varieties, I've never tried before, Accent and swift, the swift are looking fine, but the accent don't look good at all, leaves are full of holes, and some Shaw's are dying off, I have just been out having a look at them, one of the Shaw stems was broken, but you could hardly see the broken end, for ants, loads of them, they seemed to be at the sap, Ive never experienced this before, I'm 71 years old, and never knew ants to attack my potatoes before, any suggestions? please.