> An ant mill was first described in 1921 by William Beebe, who observed a mill 1200 ft (~370 m) in circumference. It took each ant 2.5 hours to make one revolution.

William Beebe, apparently.

You can click through the citation and read the excerpt. It's an amusing bit of writing about the joys of discovery.

Miniaturization: ant pedometers.

All you need to do is warch one ant for a minute or few and extrapolate.