Philosophers and psychologists make many different, seemingly incompatible parsimony claims in support of competing models of cognition in nonhuman animals. This variety of parsimony claims is problematic. Firstly, it is difficult to justify each specific variety. This problem is especially salient for Morgan's Canon, perhaps the most important variety of parsimony claimed. Secondly, there is no systematic way of adjudicating between particular claims when they conflict. I argue for a view of parsimony in comparative psychology that solves these problems, based on Sober's (1994) view that parsimony claims are claims that one model is more plausible given background theory.