In his lecture course “The Fundamental Concepts of Metaphysics” (1929–1930) Martin Heidegger repeatedly alludes to experiments with insects as examples for the relation of animals to the world. One report deals with a photograph made through the compound eye of a glow worm. By questioning what the glow worm might see, Heidegger separated animal vision from human vision as ontologically incomparable. In my paper I first show the source of Heidegger’s report and then discuss how deeper knowledge of the original (...) investigation might shed new light on Heidegger’s presentation and his conclusions. (shrink)