1 Samuel 6:10-12

10Then the men did so; they took two milk cows and hitched them to the cart, and shut up their calves at home.

11And they set the ark of the Lord on the cart, and the chest with the gold rats and the images of their tumors.

12Then the cows headed straight for the road to Beth Shemesh, and went along the highway, lowing as they went, and did not turn aside to the right hand or the left. And the lords of the Philistines went after them to the border of Beth Shemesh.