Pen

Pens are areas to contain farm animals. These can be created with a mixture of solid walls, fences, or fence gates. Colonists will automatically rope unassigned tamed farm animals and lead them to a pen. Roped animals can only pass through fence gates. Animals in a pen will be passive and will not attack hostiles, and vice versa. Humans and some predatorial animals, however, can enter a pen through either a fence or a fence gate by jumping over.

Unpenned farm animals cannot be assigned to an area like humans and pets, and will roam around, producing filth. They will also occasionally attempt to roam off the map, determined by the roam interval stat.

Clicking on a pen marker will show a tooltip about how many animals a pen can sustain without colonist intervention (through grass and brambles that grow naturally), measured in cows, sheep, and chickens. You can also set up an auto-slaughter order that kills animals when the count of a certain gender and species surpasses a set number. Pregnant and juvenile animals are not included in this count.

Rooms separated with an animal flap instead of a door will count as part of the attached pen. The animal flap can be used to create a room for animals to cool down or warm up in extreme temperatures.