Due to an increased presence of robots in human-inhabited environments, we observe a growing body of examples in which humans show behavior that is indicative of strong social engagement towards robots that do not possess any life-like realism in appearance or behavior. In response, we focus on the under-explored concept of a common locus as a relevant driver for a robot passing a social threshold. The key principle of common locus is that sharing place and time with a robotic artifact functions as an important catalyst for a perception of shared experiences, which in turn leads to bonding. We present BlockBots, minimal cube-shaped robotic artifacts that are deployed in an unsupervised, open-ended and in-the-field experimental setting aimed to explore the relevance of this concept. Participants host the BlockBot in their domestic environment before passing it on, without necessarily knowing they are taking part in an experiment. Qualitative data suggest that participants make identity and mind attributions to the BlockBot. People that actively maintain a common locus with BlockBot by taking it with them when changing location, on trips and during outdoor activities, project more of these attributes than others.