Control of bacterial adhesions to a substrate with high precision in space and time is important to form a well-defined biofilm. Here. we present a method to engineer bacteria such that they adhere specifically to substrates under blue light through the photoswitchable proteins nMag and pMag. This provides exquisite spatiotemporal remote control over these interactions. https://www.spidertattooz.com/Superdry-Organic-Cotton-Essential-Baseball-L-S-T-shirt/