Undisturbed lake sediments can be dated and used as natural archives of past changes in their surrounding environment. Pollen, leaves, hair, feces – some part of every organism that lives around a lake at a certain time ends up in the water and their eDNA is trapped in the respective layer of the lake sediment. European rabbits were introduced in a remote sub-Antarctic island during the 19th century, with potentially heavy impact on native plants because of overgrazing. How would you study whether the introduction of rabbits indeed changed the vegetation surrounding a local lake?