Without photos I'm guessing wire worms, which are the larvae of the click beetle. The larvae live for several years in the soil and attack many different plants. They are very difficult to control in home gardens. Google wireworms for more info.

ack, does that mean I can't grow potatoes without damage?

How disappointing.

thanks for the advice

Wire worm larvae move down in the soil as the soil temp increases and move back up in the spring, usually after you have planted your seed potatoes. You might consider "planting" potatoes about one to two feet apart to attract the wireworms. Then you can destroy the larvae before planting your crop of potatoes.