In siloed discussions of antimicrobial resistance, antibiotic use on farms in the Global South has emerged as a key site for intervention. The antibiotic consumption targeted is not all consumption, but “irrational” consumption. This concept of irrationality is neither new, nor true, but rather is a long‐standing form of maintenance work within global health systems. Via an attention to chickens and the antibiotics farmers use to raise them in the suburbs of Kampala, we suggest that claims of irrationality are a central part of constituting what Tania Li has called the ‘deficient subject’. In other words, irrationality, like the chicken and the antibiotic, is itself a humanitarian device that maintains a certain condition of governance where ‘Africans’ are imagined as being in deficit of rationality and good behavior. Claims of irrationality justify (and mask the political nature of) intervention.