Deleuze’s work is sometimes acknowledged for its affinity both for certain kinds of animals or ‘becomings-animal’ as well as for jurisprudence as a mode of thought in relation to law. This paper explores the close connection that Deleuze’s ‘casuistic’ conception of jurisprudence has with the method and technique of the classical Roman jurists. It does this by paying close attention to the appearance of the animal (the bees) in a fragment concerning liability under the lex Aquilia. A rather atypical and awkwardly phrased ‘case’, the example of the bees in Ulpian’s text reveals how the animal can occupy a remarkable centrality in the thought of law: not so much as metaphor but as jurisprudential ‘diagram’ capable of refining and extending juridical institutions. Offering a conception of law that can, in Deleuze’s words, ‘do without any subject of rights’, the casuistry of Roman law provides some unexpected avenues into the contemporary projects of anti-humanism and non-anthropocentrism in law.