Beginning with the premise that literature offers a space for negotiating the kinds of complexity that often attend sensitive socio-cultural issues, this project explores moments of human-animal, or interspecies, ambiguity in representations of animal experimentation. Within “Fictions of Bio-Messiness” ‘experimentation’ operates on the levels of both content and form—that is, literature with animal experimentation as its subject and texts that use innovative narrative forms to represent animal experience. To explore issues like bodily ambiguity, zoonosis, and antivivisectionism, the project is organised around five key concepts: history (WP1), ethics (WP2), affect (WP3), language (WP4), and practice (WP5). While research within the field of critical animal studies has produced a number of scholarly works on literary animals in relation to pet ownership, farming, hunting, and entertainment, there is a striking lack of scholarship on animal experimentation. This research seeks to fill this gap by (1) offering a historical survey of ‘experimental animals’ in literature from 1945 to the present; (2) providing, via close readings of select novels, a detailed exploration of the epistemological paradoxes and ethical complexities of animal experimentation; (3) identifying experimental literary forms for representing nonhuman animals in fiction; and, (4) beginning to contextualise these literary findings within broader discussions surrounding the practice of live-animal research.