Today's searches for dark matter suggest that it might interact only very weakly with the particles we observe. This insight changes our picture of how the dark matter abundance was created in the early universe. In this talk, we will test this
picture at the LHC. In a scenario with tiny couplings to the Higgs boson, I will show that dark matter is produced from long-lived particles that leave peculiar signatures in the LHC detectors. Their discovery can tell us more about the origin of the observed dark matter abundance.