Dung Beetles Navigate by the Milky Way
Dung is animal excrement, long used as fuel and fertiliser. One insect that lives on it steers by starlight.
Dung is animal excrement, valued for centuries as fertiliser and, dried, as fuel. The dung beetle rolls a ball away from the pile in a straight line to avoid rivals, and experiments in South Africa showed it steers by the band of the Milky Way — beetles fitted with tiny caps lost their bearings, and it remains the only insect known to navigate by the galaxy. *Dung* is Old English and unrelated to any polite euphemism; the plain word has simply survived.
- Animal excrement. *Cow dung.*
- Fertiliser. *Spread dung on the field.*
- Dried fuel. *Dung cakes.*
- Dung beetle. *A dung beetle.*
- Old English — *dung*. *The source.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | dung | Dung. |
| Compound | dunghill | A dunghill. |
| Compound | dung beetle | A dung beetle. |
| Related | manure | Manure. |
| Old English | dung | Dung. |
- The field was spread with dung.Farming.
- Dried dung burns slowly.Fuel.
- Dung beetles steer by the sky.Fact.
How the dung beetle navigates
- A straight line is the fastest escape from competitors at the pile
- By day the beetle uses the sun and polarised light
- By night it uses the bright band of the Milky Way
- Beetles fitted with caps lost their straight course entirely
- No other insect is known to navigate by the galaxy
Old English *dung*, of Germanic origin, related to German *Dung*.
Do dung beetles navigate by stars?
By the Milky Way as a whole rather than individual stars. Experiments showed beetles lost their straight path when the sky was blocked.
Why was dung used as fuel?
Dried dung burns slowly and steadily, and in treeless regions it was often the only fuel reliably available.