Scarab Beetle

A family of 30,000

Scarabaeidae is one of the largest beetle families, with over 30,000 species. Many are dung beetles, but the family also includes:

• Rhinoceros beetles — large horned tropical species, the world’s strongest insects pound-for-pound.
• Stag beetles (different family but related) — large, antler-jawed males.
• Hercules beetle — Central American giant, 17 cm long.
• Goliath beetles — African, among the heaviest insects on Earth.
• June beetles, May beetles, Japanese beetles — agricultural pests.

The family includes both the world’s most ecologically beneficial beetles (dung beetles) and some of its worst agricultural pests.

Egyptian sacred scarab

The sacred scarab (Scarabaeus sacer) was one of the most important symbols in ancient Egyptian religion. The Egyptians observed dung beetles rolling balls of dung across the desert and connected the imagery to:

• The sun god Khepri rolling the sun across the sky each day
• Rebirth and resurrection — the beetle larvae emerging from buried dung balls

Carved scarab amulets (“heart scarabs”) were placed on the chest of mummies to ensure successful passage to the afterlife. They were among the most-produced ancient Egyptian artifacts; thousands have been excavated.

Dung-rolling

Scarab beetles’ famous behavior is rolling spherical balls of dung to underground burrows where they’re buried as food for larvae. The technique:

1. Find fresh dung (within minutes of deposition).
2. Form a ball with the front legs.
3. Roll backward, walking on the front legs and pushing the ball with the hind legs.
4. Navigate using the sun, the moon, polarized light, or even the Milky Way as references.

Recent research found dung beetles use the Milky Way for orientation on moonless nights — the first non-human animal documented to navigate by the galactic disk.

Ecological role

Dung beetles are ecosystem engineers in grasslands. By burying dung underground, they:

• Recycle nutrients into soil
• Reduce surface fly populations (parasites of livestock)
• Aerate soil through tunneling
• Disperse plant seeds buried in the dung

In Australia, native dung beetles couldn’t process introduced cattle dung, leading to massive bush fly problems. African dung beetles were introduced as biological control in the 1960s and dramatically reduced fly populations.