public void eat(ArrayList<ParkerPaulChicken> chickens) {
        /// guard clause - no chickens to eat
        if (chickens.isEmpty()) {
            return;
        }

        // guard clause - didn't catch a chicken
        if (!canCatchChicken()) {
            return;
        }

        // select a chicken to eat and update weight and collection of chickens
        ParkerPaulChicken chicken = chickens.get(random.nextInt(chickens.size()));
        fattenUp(chicken.getWeight());
        chickens.remove(chicken);
    } // end of eat