Given that there is a living to be made at night, and alternative daytime trades are thoroughly occupied, natural selection has favoured bats.
bats
When dinosaurs dominated the daytime economy, our mammal ancestors only managed to survive because they found ways of scraping a living at night
ancient human
Blind people, without even being aware of the fact, are actually using echoes of their own footsteps and of other sounds, to sense the presence of obstacles
footstep
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