This paper questions Heidegger’s interpretation of animals in his 1929-1930 seminar, The Fundamental Concepts of Metaphysics: World, Finitude, Solitude. Heidegger denies that animals have access to the ‘as such,’ to beings as such, and yet it must be asked if he can maintain this. His course is open to two interpretations: either we deny that the binding, encountering, struggling, and adapting that Heidegger attributes to animals are possibilities for animals, and we thereby make the animal what I call ‘the impossible’—and I provide additional reasons against this option by arguing against Heidegger’s interpretation of the central bee experiments—or we retain binding, encountering, struggling and adapting in line with my argument and thereby see animals as diversified: each kind of animal has different drives/disinhibitions, and so each is in a different kind of ‘world.’ To make this argument, Derrida’s later work on this seminar is drawn upon. Derrida’s particular deconstructive strategy of asking whether the human actually has what it attributes to itself is not pursued here; however, a related deconstructive strategy, concerning questioning the purity of the animal realm, is deployed. Making the animal realm pure is the result of an operation of a sacrificial structure: animals are sacrificed to maintain the abyssal difference of the human. This sacrifice, and the suffering it allows, is enabled by the denial that animals are open to beings ‘as such.’