When the scraps are added, the worms move through the bedding and consume the scrap. In a sense, the bedding serves as their 'road'. Ideally, the worms should live in a 60 - 70 degree environment. They also need bedding to live in. This can be made from any non-toxic paper product, such as newspaper, paper bags, small animal bedding, grass clipping, or leaves.
Humidity is very important to the worms.
If there is too much liquid in the bin, they will drown, and if there is too little, they will suffocate. Luckily, this is simple to manage. When adding bedding, first submerge it in water. Then, before adding it to the bin, squeeze it until it doesn't drip excessively. Then simply open the spout on the front of your bin every week or so to collect any excess nutrient-rich liquid.