This is a big one, if you’re keeping your bin indoors don’t add outdoor soil, leaves, grass clippings or outdoor compost. And don’t bring your bin outside for the summer and in for the winter.
Outdoor waste could have potential outdoor critters nesting in it and bringing it inside could mean having them hatch in your home, yuck!
I’ve considered leaving a bigger worm bin outside on my balcony and just letting the worms fend for themselves in the winter then add more worms from my indoor bin each spring if they didn’t survive. This would let me collect more compost and also allow me to add outdoor waste from my garden into my outdoor bin.