Back in 2012, McDonald’s announced it was starting to phase out pork from farmers using gestation stalls. Gestation stalls are a housing system for pigs. This type of housing system tends to reduce aggressive behavior as pigs can be rather belligerent creatures, particularly toward one another. An alternative to gestation stalls is group housing. The question as to which is right isn’t obvious; research has found that both gestation stalls and group housing have unique benefits and drawbacks.