The Darkling Beetles are a very large and very diverse family of beetles. They have been divided into eight sub-families, which, in Australia, together contain over 1600 species in over 200 genera. Tenebrionids are also found in South America, which suggests a Gondwanan origin.

Darkling Beetles are usually black or dull brown in colour, though some are metallic. Their shape may be round or elongated and their upper surfaces may be ridged or intricately patterned with dimples. They range in size from 2 mm to 35 mm.

Adult beetles feed mostly on fungi, but they also eat decaying plant matter, fresh flowers, seeds, roots and leaves. Some species live in a close relationship with other insects and vertebrates. A number of Darkling Beetles are considered agricultural pests as they damage foodcrops and stored grains. Mealworms are the larval form of the Mealworm Beetle, Tenebrio molitor, a species of Darkling Beetle. Darkling larvae more typically feed on rotting wood.