Adult warehouse beetles average about 3.2 mm (0.13 in) in length and are some shade of reddish-brown, dark brown or blackish-brown.

The larvae are cream coloured or some darker shade of brown, and average 6 mm (0.24 in) in length when fully grown; they have long bristles at the tip of the abdomen.

It also infests animal detritus, fish meal, spices, nuts, cocoa and sugar products.

[1] In the indoor environment it occurs in warehouses, granaries, food stores and dwellings, and outdoors in Russia, it has been found in bee nests.

There are normally six instars, and some mature larvae enter an active diapause, especially in cooler habitats, and may remain in the larval state for two years.