In this article, we present a numerical study of unsteady flow and heat transfer in a viscous‐based nanofluid, examining the impact of microorganisms on a moving surface emerging from a moving slot. This gives rise to a new type of boundary layer flow, which can resemble that over a stretching or shrinking surface depending on the motion of the slot. To solve the partial differential equations governing the bio‐convectional flow, we employ the Blasius–Rayleigh–Stokes variable and transform the equations into a corrected similar form. Our numerical solutions reveal the presence of dual solutions within a specific range of the moving slot parameter. Our findings have important implications for understanding the behavior of nanofluids and microorganisms in dynamic flow environments.