  We investigate theoretically the ballistic motion of small legged insects and
legless larvae after a jump. Notwithstanding their completely different
morphologies and jumping strategies, these legged and legless animals have
convergently evolved to jump with a take-off angle of 60$^\circ$, which differs
significantly from the leap angle of 45$^\circ$ that allows reaching maximum
range. We show that in the presence of uniformly-distributed random obstacles
the probability of a successful jump is directly proportional to the area under
the trajectory. In the presence of negligible air drag, the probability is
maximized by a take-off angle of 60$^\circ$.
  The numerical calculation of the trajectories shows that they are
significantly affected by air drag, but the maximum probability of a successful
jump still occurs for a take-off angle of 59-60$^\circ$ in a wide range of the
dimensionless Reynolds and Froude numbers that control the process. We discuss
the implications of our results for the exploration of unknown environments
such as planets and disaster scenarios by using jumping robots.
