Violet ground beetle

Violet ground beetles are flightless beetles, with a black head, thorax and abdomen black with purple lateral margins, and black underside, antennae, and legs. The antennae measure half the length of the body; the thorax is nearly heart-shaped, scalloped at the front and bordered at the back; the elytra are joined, smooth and without ridges or indentations, but do have tiny bumps arranged in "indistinct lines". The body is usually between 2 and 3 centimetres (0.79 and 1.18 in) long. The species appears similar to Carabus problematicus, but the colour on C. violaceus' pronotum is more extensive.

The species is distributed across the Euro-Siberian region. It is common throughout Great Britain.

Violet ground beetles live in woodlands both ancient and recent and some adjacent habitats. Because they are flightless and restricted to forested habitats, they are vulnerable to habitat fragmentation and have low dispersal ability: one study showed that only a few kilometres of grassland were enough to render the beetles unable to settle in forests on the other side. However, the subspecies C. violaceus picens is known to inhabit high-altitude pastures. Stomach content examinations have meanwhile shown that jackdaws sometimes feed their nestlings violet ground beetles, among other insects, and that blackbirds also sometimes eat the beetles.