The Leaf-Cutters 'Waste Disposal Chamber' or Waste Chamber for short, is used for the one specific purpose of increasing the Fungus Gardens throughput/capacity. These should only be used when your Garden has already reached a 50% bonus. This nest is useless without a Fungus Garden. These are typically built late in the game, when you have a large healthy income.

Cost: 40 food
Income Bonus: +4 capacity
Time: builds slowly
Death: leaves an opening when destroyed