The family has received considerable taxonomic attention in recent years and now consists of 70 species distributed in five genera.

[1][2][3][4][5][6] It was indicated Cucujus species are scavengers, only feeding on pupae and larvae of other insects and on other subcortical beetles such as their own.

Heads are triangular in shape, with filiform to moniliform antennae of 11 antennomeres, and large mandibles.

[11] Cucujus clavipes puniceus (red flat bark beetle) found in arctic regions like Canada and Alaska [13] desiccates to 30–40% body water in winter vs 4% body water in the chironomid fly, Polypedilum vanderplanki.

It uses a variety of anti-freeze proteins[14][15] in contrast with the non-protein xylomannan exploited by another arctic beetle Upis ceramboides.