I will present two topics we are currently working on in the lab. The first one concerns fluidic networks, which are pervasive in all clades of biology, from the vasculature of animals and plants to the  plasmodia of slime molds and the mycelia of fungi. In contrast to man-made flow networks, such as the porous media making up batteries, living networks self-organize. One of their main task is to transport signalling molecules or nutrients, so that all parts of the organism are perfused with the same amount of solute. We will show how we can experimentally make microfluidic networks whose walls erode in response to a chemical. This modification in geometry enables to start with a random fluidic network, and make it evolve to a network where all branches have the hydraulic resistance, which is close to optimal for perfusion. Experimental results are in very good agreement with theoretical simulations.  In a second part, I will show our ongoing work on the transport of passive plastic beads by microalgae which are 50 times smaller than the beads. Manipulating the local concentration of microalgae with light, we can create millimetric flows that are used to transport the beads directionally.