“Living” liquid crystals combine the properties of human-made liquid crystals with features of swimming bacteria. Scientists built an accurate model of how the crystals control the motion, transport and position of swimming bacteria. The model can also simulate how other particles behave in the living crystal. Now, scientists can combine the model with on-demand synthesis and the ability to guide defects that direct the bacteria or particles. The result? This work could lead to self-healing and shape-changing materials. The materials could manage complex processes, such as producing power.