Entology: A Design Research Framework for Modelling Behavioural Presence (V1) introduces an infrastructural approach to the study and construction of "entities" as active agents within lived and simulated environments. Moving beyond traditional ethology and psychology, this framework formalizes the study of presence as an operational system, integrating behavioral consequences with environmental, cultural, and algorithmic vectors. Core Framework Components: The Four Irreducible Nodes: A structural taxonomy consisting of Mechanism (Apex), Manifestation (Condition), Function (Consequence), and Origin (Vector). Operational Modelling: A mathematical and systemic relation for presence defined as $Presence = System \times State \times Signal \times Interpretation$. Game Balance as Entological Practice: A minimalist systemic model utilizing Source, Pool, and Drain flows to regulate patterned consequences in interactive environments. Design Research Methodology: Alignment with Frayling’s (1994) categories of Research on, for, and through Design. Status of the Work: This document (V1) represents a foundational iteration of the Entology framework. It is currently being operationalized as a game balance tool and research framework for the analysis of domestic and hauntological spaces, where presence emerges through trace, repetition, and absence. This is an "in-progress" working paper intended to provide a durable grammar for researchers in game design, architecture, and human-computer interaction.