Since the 1980s, archaeologists have challenged the idea that prehistoric actions were guided primarily by practicality and expedience. Rubbish disposal, a superficially mundane activity, provides a critical case for exploring the depth to which cultural logics penetrate. Ethnoarchaeological research on discard behaviour in Mesoamerican houselots has modelled rubbish disposal as a matter of expedience predictable by factors such as density of settlement and length of occupation. At the Classic period site of Chunchucmil, Yucatan, such models based on practical reason succeed only partly in predicting the distribution of rubbish. Ethnographic and ethnohistorical accounts of rubbish in Mesoamerica suggest that fully understanding its distribution requires attention to cultural logics. At Chunchucmil, ancient Maya cosmology explains the location of dumps within households. Thus, both practical and cultural logics structured discard. The case of Maya subsistence farming suggests that practical logic is subsumed by cultural logic, rather than the two logics conflicting. These findings show how broadly-held beliefs and predispositions are instantiated and reproduced in daily life.