Pen

Pens are areas to contain farm animals. These can be created with a mixture of solid walls, doors, animal flaps, 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. Be aware that all pawns except farm animals (including predatorial animals), 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 large amounts of filth, which is reduced by a factor of x0.05 by the straw matting floor. A minor, permanent warning will appear, reminding you to either pen the animal or place straw matting. They will also occasionally attempt to roam off the map, determined by the roam interval stat. The game will also give a temporary warning in the top left of the screen if this happens.

Clicking on a pen marker will show three buttons, each containing useful information and configurations for a pen. The first tab is used to configure which species of animal is allowed in the pen. The second shows how many animals a pen can sustain without colonist intervention (through grass and brambles that grow naturally), measured in cows, goats, and chickens, including an option to force display other animals in the count. The third tab allows you to set up auto-cut orders for plants. You can also set up an auto-slaughter order in the animals tab that sets a slaughter job for animals when the count of a certain gender and species surpasses a set number. Juvenile animals are not included in this count, but pregnant animals can be allowed. The auto-slaughter will mark animals in the order of oldest to youngest, and will mark pregnant animals (if allowed) in the order of their pregnancy (most recent to least recent).

Rooms separated from the pen 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 sleep in, cool down, or warm up in extreme temperatures.