Often confused with the larger but similarly shaped lion’s mane jellyfish, the blue jellyfish can be colourless when young and develop a striking blue-purple bell as it matures.

The serotine is one of the first bats to appear at night and can be seen around lamp posts chasing moths, or at treetop height. It likes to roost and hibernate in old buildings in the south of the…

Often seen carpeting the floor of ancient woodlands, Dog's mercury can quickly colonise, its fresh green leaves shading out rarer plants. It is also very poisonous.

Look out for the small holly blue in your garden or local park. It is the first blue butterfly to emerge in spring, and a second generation appears in summer. The caterpillars are fond of holly…