Multi-Layer Vermiculture Bin

Step 4: Drill a few Air Holes

Drill 3/8” holes at very top of second bin on sides (not lid.) These holes will promote air circulation and prevent anaerobic conditions. Make sure that they are located on the top of the bins where the lid will prevent any water from getting in and making things too wet. If it is your intention to keep your bins inside, which is easily done, than you need not worry about the rain factor and can place your air holes wherever you like on the top bin.