What lives under logs?

Use our ID guide to identify invertebrates living unders logs and stones during winter. 


Winter can be a bleak time for invertebrates – many are taking refuge under logs and stones, safe from damaging frosts. Turn one over briefly and discover a tiny new world. Illustrations by Felicity Rose Cole


1. (above) Violet ground beetle Carabus violaceus

20–30mm. Large beetle with purple wingcase borders. Feeds on worms and other soft-bodied invertebrates.

2. Woodlouse spider Dysdera crocata

9–15mm long. Found most frequently in southern England. Its huge orange jaws pierce woodlouse armour.

3. Buzzing snail-hunter Cychrus caraboides

15–20mm. Long ‘snout’ probes snail shells. Also eats wide range of soft-bodied prey. Buzzes when handled.

4. Ground beetle Abax parallelepipedus

17–22mm. Black beetle with grooved wingcases. Eats earthworms and other soft-bodied invertebrates. 

5. Carrion beetle Silpha atrata

10–15mm. Mat-black beetle with broad wingcases. Feeds on snails and a wide variety of carrion.

6. Devil’s coach-horse Ocypus olens

20–30mm. Black rove beetle with short wingcases. Raises tail when threatened. Eats slugs.

7. Common black millipede Tachypodoiulus niger

Up to 30mm. Coils when disturbed. Body has 30–60 segments. Feeds on decaying matter and fungi. 

8. Flat-backed millipede Polydesmus angustus

Up to 25mm. Brownish, winged segments; appears flatter than black millipede. Often found under bark. 

9. Common pill woodlouse Armadillidium vulgare

Up to 18mm. Found especially on limy soils. Similar pill millipede has more than seven pairs of legs. 

10. Common striped woodlouse Philoscia muscorum

Up to 11mm. Fast-moving. Grey, brown or even orange, often with dark stripe. 


11. Garlic snail Oxychilus alliarius

6–8mm. Translucent, shiny, pale-brown shell, dark grey body. Emits strong garlic smell when disturbed

12. Great grey slug Limax maximus


Very large slug, up to 20cm. Body dark grey, with paler blotches and stripes – hence alternative name of leopard slug.