Critter Barriers
This mod provides the ability to create functional barriers in the form of rope and chain curtains. These structures allow players and most large creatures to pass through, but effectively block the movement of small mobs that simply don't have enough strength to push through them.
A key feature of the mod is a fully customizable data-driven access control system. This offers flexible integration possibilities with other modifications - you can independently specify which exactly creatures will be able to pass through the barriers and which will remain blocked.