Tadpoles take blame for human hiccups Why do we hiccup? It's a question that has vexed great minds for millennia and now, at long last, an international team may have come up with the answer. Hiccups are sudden contractions of the muscles we use to breathe in. Just after the muscles start to move, the glottis shuts off the windpipe, producing the characteristic "hic" sound. Surprisingly, ultrasound scans reveal that babies in the womb start hiccuping after two months, before any breathing movements appear. That suggests that hiccups in adults are just the remnant of some primitive reflex, which occur...