Queen creates workers who look for food & return to the queen.

queen-foraging.js

// set basic attributes here;
// "this" means this ant you're editing now
ant.speed = 1;
ant.trailColor = 'red';
ant.height = 40;
ant.width = 40;
ant.energy =  5000;

// runs every frame:
onRun = function () {

  ant.direction += Math.random()*10-5; // vary direction slightly, randomly, in degrees
  ant.trail(ant.trailColor, 100); // leave a trail of <color>, <amount>
  ant.color = "rgba(" + ant.energy + ", 0, 50, 1)"; // color red according to how full

  // if queen has enough energy, and there are <100 ants on the field
  if (ant.energy > 1000 && field.objects.length < 100) {

    // make a new ant:
    var child = field.populate(AntFarm.Ant, 1)[0];

    // give child 1000 energy:
    child.energy = 1000;
    ant.energy -= 1000;
    child.x = ant.x;
    child.y = ant.y;
    child.speed = 3;
    child.queen = ant;
    
    child.onRun = function() {

      // uncomment this line for debugging energy; each ant will have a label
      // child.el.html('  '+parseInt(child.energy)); // display energy

      // if on top of some food and mood is not purple:
      if (child.color != 'purple' && child.green() > 0) { // eat
      
        child.color = 'yellow';
        child.energy += child.green();
        child.green(0); // remove the green from that patch
        child.foodPlace = [child.x, child.y]; // remember that spot
        if (child.energy > 1000) child.color = 'purple'; // return to queen if full
        
      } else if (child.color == 'purple') { // return to queen
        
        if (child.distance(child.queen) < 20) { // if already near queen
          
          child.color = 'yellow';
          child.speed = 0;
          child.queen.energy += child.energy/2;
          child.energy /= 2;

        } else {  // point at queen, fast!

          child.speed = 4;
          child.point(child.queen);

        }
        
      } else if (child.foodPlace) { // return to foodPlace

        child.color = 'orange';
        child.speed = 4;
        // point at food place, but
        // don't keep pointing when close to food or you get stuck:
        if (child.distance(child.foodPlace) > 5) child.point(child.foodPlace);
        else child.direction += Math.random()*90-45; // or just wander

      } else { // forage

        child.color = "rgba(" + child.energy + ", 0, 50, 1)"; // color red according to how full
        child.speed = 2;
        child.direction += Math.random()*10-5; // random walk

      }

      // if child runs out of energy
      if (child.energy <= 0) {

        child.color = 'grey';
        child.die();

      }

      // leave a trail
      child.trail(ant.trailColor, 255); // color, amount 0-255

    }
    
    child.remember(); // make child ant remember their instructions! 
  }
}

onBump = function () {

  // change direction by 90 degrees:
  ant.direction += 90;

}