  Cells have evolved efficient strategies to probe their surroundings and
navigate through complex environments. From metastatic spread in the body to
swimming cells in porous materials, escape through narrow constrictions - a key
component of any structured environment connecting isolated micro-domains - is
one ubiquitous and crucial aspect of cell exploration. Here, using the model
microalgae Chlamydomonas reinhardtii, we combine experiments and simulations to
achieve a tractable realization of the classical Brownian narrow escape problem
in the context of active confined matter. Our results differ from those
expected for Brownian particles or leaking chaotic billiards and demonstrate
that cell-wall interactions substantially modify escape rates and, under
generic conditions, expedite spread dynamics.
