All changes listed should work, I am having some trouble testing as the ants are not wandering correctly, but wanted to push.

1. Ants lay breadcrumb trail of pheromones as they near food.

2.
-young worker (age 1-60% of life expectancy, but we can change this):will seek closest detected food (or pheromone) to bring back to nest. Radius of search will be medium range to nest. If unable to find food will return to queen, eat, and set out again.

-middle aged worker (60-90% of life expectancy):  will patrol small radius of nest

-old worker (90-100%): least common ant will have an increased food level and speed. Similar to young worker, but with a LARGE radius to nest

3. Middle aged "soldiers" watching out for other species of ant, ready to fight or run depending on health.