It is known that soil biota affects water dynamics through various complex mechanisms. The impact on retention by soil biota are due to a combination of changes to pore geometry, pore clogging by biofilms, biofilms that serve to connect thin water films across many pores as the soil dries, and to changes in the properties of the biofilm during the drying process. This study explored the physical properties of biofilm in a natural sandy soil. Specifically, we studied the role that microbial exudates play in water retention during drainage and in water connectivity during evaporation. During early stages of evaporation, pores containing biofilm support capillary flow through a continuous liquid network that delivers water up to the soil surface. This enhanced connectivity by microbial exudates extends the duration of Stage I evaporation and increases the depth of the drying front. As matric potential increases, microbial stresses may result in alterations to the biofilm and how it interacts with soil moisture, subsequently changing pore scale transport mechanisms. During drainage, soils with biofilm held more moisture than an abiotic soil in which the biofilm had been destroyed. The study confirmed that biofilms may serve an important role in sandy soils by providing a connected network for water delivery to roots in a porous media with otherwise low capillary potential.