  We discuss the possibility of entanglement islands in cosmological spacetimes
with a general perfect fluid with an equation of state $w$. We find that flat
universes with time-symmetric slices where the Hubble parameter vanishes always
have islands on that slice. We then move away from such slices, considering
still universes with a general perfect fluid. Under the local thermal
equilibrium assumption, the comoving entropy density $s_c$ is constant. As a
result, the conditions for an island become an inequality between the energy
density (or Hubble parameter) and the temperature at some time of
normalization. The consequences are that islands can exist for practically all
fluids that are not radiation, i.e. $w\neq 1/3$. We also discuss the
ramifications of our results for universes with spatial curvature. Finally, we
show that islands occur in the Simple Harmonic Universe model which has no
classical singularity at the background level, in contrast to all previous
examples where islands occurred only in space-times with singularities.
