An ant script saved from https://github.com/jywarren/antfarm

followBlue.js

onRun = function() {

  var redness = lookFor('blue',3);
  
  if (redness == "N") this.direction = 0;
  if (redness == "E") this.direction = 90;
  if (redness == "S") this.direction = 180;
  if (redness == "W") this.direction = 270;
  
  this.direction += Math.random()*10-5;
  field.trail(this.x, this.y, 'red', 50); // x, y, rgb, amount

}

onBump = function() {

  this.direction += 90;

}