Scarabs are stout-bodied beetles, many with bright metallic colors, measuring between 5-60 mm. They have distinctive, clubbed antennae composed of plates called lamellae that can be compressed into a ball or fanned out like leaves to sense odors. The front legs are broad and adapted for digging.
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 devastating agricultural pests.
In ancient Egypt, scarabs were revered as sacred. Some of the well-known beetles from the Scarabaeidae are Japanese beetles, dung beetles, June beetles, rose chafers, rhinoceros beetles, Hercules beetles and Goliath beetles.
Several members of this family have shells which act as left-handed circular polarisers; this was the first-discovered example of circular polarization in nature.