Biology
How do hiccups help our body maintain balance?
Quick fact
Hiccups are caused by involuntary spasms of the diaphragm, followed by sudden closure of the vocal cords, producing the characteristic 'hic' sound.
Why this is interesting
Hiccups are a reflex that serves no obvious purpose in adults—but they're nearly identical to the breathing mechanism of tadpoles, suggesting they're a ghost of our aquatic evolutionary past.