H Home Base Ilan Golani 1 and Yoav Benjamini 2 1 School of Zoology, and Sagol School for Neuroscience, Tel Aviv University,Tel Aviv, Israel 2 Department of Statistics and Operation Research School of Mathematics, and Sagol School for Neurosciences, Tel Aviv University,Tel Aviv, Israel A conspicuous spatial regularity in the explor- atory behavior of many organisms is the existence of a home site or home base. In the wild, animals have such a site to which they return regularly after exploring their home range or territory, be they, e.g., ants, bumble bees, millipedes, small mammals, or wolves. In behavioral neuroscience experiments, the animal’ s “home base” refers to its most preferred place, from which it performs excursions or forays into the environment (Eilam and Golani 1989). Upon being introduced into a novel laboratory arena, rats establish one or two places that stand out in terms of the time spent in them, the number of visits paid to them, and the incidence of grooming, and other behaviors that are typically performed in them, like crouching, turning in place around the forequarters, and the high frequency of rearing episodes performed in them. An accumulation of time through a high number of visits also characterizes the home base of, e.g., mice (Fonio et al. 2009; Benjamini et al. 2011), infant rats, and zebra fish (Stewart et al. 2010). The conspicuousness of the home-base phe- nomenon begs an examination of its significance in spatial cognition. One common way of study- ing spatial cognition involves the study of maplike representations of physical space in the brain and the computational and neural analysis of naviga- tional strategies involving different ways of infor- mation processing like piloting, dead reckoning, and the use of cognitive maps. The cognitive significance of the home base has been studied by using a complementary, ethological strategy, of obtaining a view on the organization of spatial cognition by studying the growth and differentia- tion of moment-to-moment spatial behavior (Gomez-Marin et al. 2016). On a large platform placed away from walls, devoid of objects or markers, each individual rat will establish its own home base in a specific place, often at a corner but sometimes in the center area, in a location that is idiosyncratic to it. The selection of a location and the establishment of a home base in it thus reflect an endogenous con- straint, characterizing the organization of explor- atory behavior, independent, at least partly, of proximal features located in the environment. Home base location constrains cognitive spatial behavior. The home base exerts its influence on the rodent’ s behavior across the entire explored area. Visits to the home-base partition the path into excursions in the environment. The latter are # Springer International Publishing AG 2018 J. Vonk, T. K. Shackelford (eds.), Encyclopedia of Animal Cognition and Behavior, https://doi.org/10.1007/978-3-319-47829-6_920-1