“Worms breath thru their skins so do worm bins need ventilation? I’m planning on building an insulated worm bin. Should I include a ventilation tube to allow a fresh air supply?” ~ Bruce Novell
You are absolutely right about worms needing to breathe through their skins.
Worms are like us, and breathe in oxygen while breathing out carbon dioxide.
Worms have a permeable skin which allows the diffusion of gas through their skins into their blood vessels. This diffusion requires their skin to be constantly moist, which is why if you dry them out you are basically suffocating them!
If making worm bins, it is advised to add some air holes in the lids or around the sides. If you have bought one, you will realize that many of them will already have holes within them to allow the system to breathe.
It seems that you are in a cold place and are looking for a decent way to insulate the bin (which will cover a lot of the breathing holes) while not suffocating the system by not providing enough air. A ventilation tube is a great idea!
I will also suggest adding mesh on both opening ends to prevent the chance of worms escaping and unwanted visitors from getting in. Also be careful where the tube end is placed if it is long. You would not want the opening to be clogged up by rain, snow, dirt etc.
Thanks for sharing!