Farm Animals

Pig Nesting Behavior and Farrowing Welfare

The nesting behavior drive in sows prior to farrowing is one of the most strongly motivated behaviors in farm animals, and its frustration in crates causes intense suffering.

Key Facts

Sows begin intense nest-building activity approximately 24 hours before farrowing, collecting and arranging material
In the absence of nesting material, sows perform repetitive rooting and pawing at bare surfaces for hours
The motivation to nest increases with time since onset and does not habituate — frustration intensifies without substrate
Providing straw before farrowing dramatically reduces stereotypic nesting behavior and appears to reduce stress

Welfare Considerations

Sow nesting motivation at farrowing is one of the clearest examples of behavioral need causing genuine suffering when frustrated. The repeated, escalating attempts to nest on bare crate floors are distressing to observe and represent intense psychological suffering in an animal with no ability to meet a pressing biological drive. Providing straw even in otherwise constrained systems delivers a meaningful welfare improvement.

What You Can Do

Support pork from farms that provide nesting material to sows before farrowing
Advocate for mandatory nesting material provision as a minimum welfare standard for farrowing sows
Support free-farrowing systems that allow full nest building behavior alongside movement
Donate to welfare organizations documenting and promoting nesting material provision on farms
Share the science of sow nesting motivation widely to build support for farrowing welfare reform