That will depend on your management....you shouldn't need added ventilation but if you overdo your hydration (veggies) or are in a naturally humid place you may notice excess moisture needing vented. I only drill in these bins that I build because the bottom section needs vented.Does it seem necessary to drill ventilation holes? There’s a 1/16-1/8 inch gap between the drawers... I’m really hoping it’s warm enough in here for them as well.