Therefore you shall make images of your tumors, and images of your mice that mar the land; and you shall give glory to the God of Israel: peradventure he will lighten his hand from off you, and from off your gods, and from off your land.
"Milch" cows (1 Samuel 6:7; 1 Samuel 6:10) are cows that are still nursing their calves. It would be very unusual for nursing cows to leave their young and head for a town some 10 miles away. Indeed the Philistines regarded this behavior as miraculous and indicative that Yahweh had been punishing them.