What does it mean if the vermicomposting bin begins to smell?

Smelling of a vermicomposting bins is an indicator that there is something wrong within bin.

Some of the common culprits for the smelling of vermicomposting bin are listed as below:

• There is smelly food in the bin – Some food items do not smell pleasant while decomposing. Such food items can be removed from the bin.
• It is too wet – This problem can be resolved by not adding any water or items with high percentage of water. It can also be resolved by increasing the dry bedding.
• There is insufficient ventilation – This can be addressed by frequently mixing contents of the bin or by adding fresh bedding.
• There are non-compostable elements in the bin – Some sources of food cannot be fed to the worms because they become rancid while decomposing.