Predicting dry friction and wear involves quantifying the rheology of third bodies. At the contact scale, the rheology of solid third bodies are usually characterized qualitatively from a global morphology of the third body. At the submicrometric scale, third body particles contain information related to degradation processes. This study consists in setting up tools allowing to couple the two scales with fine resolution in both space and time. First, third bodies are generated from a steel-steel contact, under reciprocating kinematics, using a laboratory-made tribometer implemented into an environmental scanning electron microscopy (eSEM). The environmental conditions are vacuum or different water vapor pressures (humid conditions). The acquisition images conditions have been optimized. Friction factor is computed as a function of the cycle number to analyse its variations in space and time (rheological data). Images of the friction track are acquired after every 10 cycles and processed using a digital image analysis tool. The co-occurrence matrix is used as a texture study tool. This matrix is calculated on third body images on selected areas of interest. Then different quantities (homogeneity, energy, entropy …) can be calculated. This small-scale dynamic analysis allowed to follow up the formation of the third body during the running-in period. The proposed tools gave first quantitative results to improve our understanding of the mechanisms involved in friction phenomenon.