The most abundant organisms on Earth are bacteria, which play significant roles ranging from health and disease, to biogeochemical cycles and the productivity of the oceans. Our group studies different aspects of bacteria as model systems. One focus is on using multicellular cyanobacteria as models of morphogenesis and pattern formation and to study the effects of multicellularity on the function of coupled circadian clocks. Another focus of interest is in understanding in vivo molecular dynamics and search processes on long genomes relevant for horizontal gene transfer, within bacterial cells. Lastly, we have recently commenced studies on bacterial communities to understand their ecology and the role of space and time in their auto-organization and assembly. For this purpose, we use bacteria of ancient origin, predating animals and plants, whose understanding has also astrobiological implications.