from
Karnak temple of Amun-Ra, Egypt Scarabs are stout-bodied beetles; most are brown or black in colour, but many, generally species that are diurnally active, have bright metallic colours, measuring between . The
antennae of most species superficially seem to be knobbed (capitated), but the several segments comprising the head of the antenna are, as a rule, lamellate; they extend laterally into plates called
lamellae that they usually keep compressed into a ball. Then, when following a scent, such a beetle fans the lamellae out like leaves to sense odours. Many species are
fossorial, with legs adapted for digging. In some groups, males (and sometimes females) have prominent horns on the head and/or
pronotum to fight over mates or resources. The C-shaped
larvae, called grubs, are pale yellow or white. Most adult beetles are nocturnal, although the flower chafers (
Cetoniinae) and many leaf chafers (
Rutelinae) are active during the day. The grubs mostly live underground or under debris, so are not exposed to sunlight. Many scarabs are scavengers that recycle dung,
carrion, or decaying plant material. Others, such as the
Japanese beetle, are
plant-eaters, wreaking havoc on various crops and vegetation. Some of the well-known beetles from the Scarabaeidae are Japanese beetles,
dung beetles,
June beetles, rose chafers (
Australian,
European, and
North American),
rhinoceros beetles,
Hercules beetles, and
Goliath beetles. Several members of this family have
structurally coloured shells which act as left-handed circular polarizers; this was the first-discovered example of
circular polarization in nature. == Ancient Egypt ==