  From microscopic fungi to colossal whales, fluidic ejections are a universal
and intricate phenomenon in biology, serving vital functions such as animal
excretion, venom spraying, prey hunting, spore dispersal, and plant guttation.
This review delves into the complex fluid physics of ejections across various
scales, exploring both muscle-powered active systems and passive mechanisms
driven by gravity or osmosis. We introduce a framework using dimensionless
numbers to delineate transitions from dripping to jetting and elucidate the
governing forces. Highlighting the understudied area of complex fluid
ejections, this work not only rationalizes the biophysics involved but also
uncovers potential engineering applications in soft robotics, additive
manufacturing, and drug delivery. By bridging biomechanics, the physics of
living systems, and fluid dynamics, this review offers valuable insights into
the diverse world of fluid ejections and paves the way for future bioinspired
research across the spectrum of life.
