Tissues are assemblies of large numbers of cells, which form a soft active material. Their dynamics are governed by chemical signals between cells, which both coordinate active mechanical processes and also give rise to fluid flows and to electric fields and currents. In the first part of my talk, using vertex model simulations and a continuum description, I will show how cell-cell rearrangements and active fluctuations make tissues behave as nonlinear viscoelastic fluids. In particular, I will briefly discuss the energetics of cell rearrangements and how chemical work shapes tissues. Then, I will focus on the electrohydraulic properties of tissues. Using a continuum description, I will highlight the different mechanisms that are involved in the nucleation of water-filled cavities in tissues, called lumens. In addition, I will discuss how external currents or flows, imposed for instance via micrometric drains or electrodes, can be used to control tissue growth.