The common octopus is a highly intelligent, active predator. It even has a secret weapon - special glands produce a venom that it uses to incapacitate its prey!

The tiny, brown-and-white sand martin is a common summer visitor to the UK, nesting in colonies on rivers, lakes and flooded gravel pits. It returns to Africa in winter.

The bearded tit is an unmistakable cinnamon-coloured bird of reedbeds in the south, east and north-west of England. Males actually sport a black 'moustache', rather than a beard!

The black poplar is a large tree of floodplains, flooded gravel pits and ditches, particularly in England. Despite being an important part of our culture for centuries, it has declined massively…

The emperor dragonfly is an impressively large and colourful dragonfly of ponds, lakes, canals and flooded gravel pits. It flies between June and August and even eats its prey on the wing.

The bronze-coloured bream can be seen gathering in large shoals in lowland ponds, lakes and slow-flowing rivers. It is a member of the carp family and looks similar to the dace, chub and rudd.

The disc-shaped leaves and straw-coloured flower spikes of Navelwort help to identify this plant. As does its habitat - look for it growing from crevices in rocks, walls and stony areas.

A dark, stocky warbler, the Cetti's warbler is most likely to be heard, rather than seen - listen out for its bubbling song among willow, marsh and nettles.

The Black-tailed skimmer is a narrow-bodied dragonfly that can be seen flying low over the bare gravel and mud around flooded gravel pits and reservoirs. It is on the wing from May to August.