In a recent study with potential wide-reaching influence, Edsinger and Dolen (2018) tested, for the first time, the effect of 3,4-methylendioxymethamphetamine (MDMA) in the cephalopod mollusk Octopus bimaculoides. In their main experiment (Experiment 2), the authors placed octopuses in the central compartment of a three-chambered arena and allowed them to freely explore the lateral chambers, one containing an object and the other containing a social stimulus (a familiar male conspecific), both isolated through a perforated plastic container. All subjects first received a pre-trial to establish a baseline for the social response toward the conspecific, and following the administration of MDMA, they were given a post-trial with the same individual. According to the authors, the results demonstrate that MDMA induces both quantitative (i.e. longer intervals spent in the social stimulus chamber) and qualitative (i.e. different behaviors) acute prosocial responses in octopus. Here we highlight fundamental flaws in the study, thus challenging the authors’ conclusions.