Best time to see: mid Mar to mid Oct

Key facts

Harmless snake often seen in gardens and damp places; yellow collar with a black border is distinctive

Habitat: well-vegetated areas in reach of fresh water, including suburban gardens

Widespread across nearly all of Europe, but numbers are declining in many areas; legally protected

Recognition

Usually olive-green or grey, with darker blotches and a yellow collar with a black border; adults usually about 80cm, occasionally up to 200cm

Largely diurnal but very elusive; swim well; may hiss and strike when disturbed but rarely bite

Eat frogs and toads, occasionally small mammals and nestlings

Lifecycle

Lay leathery eggs in rotting vegetation such as garden compost heaps; several batches from June to Sept

Young emerge from the eggs in September and look for a winter refuge

Stay underground in semi-torpor for 5–6 months over winter