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.

The gudgeon is a bottom-dwelling fish, similar to the stone loach, but with only two whisker-like barbels near its mouth. These sensory organs help it to find its prey in the sand and gravel of…

In April and May, our ancient woodlands are awash with the much-loved, nodding heads of the bluebell. Millions of bulbs can exist in just one wood, giving rise to the 'blue carpets' that…

The stone loach is notoriously hard to spot - not only is it mostly nocturnal, it is also well camouflaged and can partially bury itself in the riverbed. It uses its whisker-like barbels to find…

In April and May, our ancient woodlands are awash with the white, starry flowers and smell of wild garlic. Millions of bulbs can exist in just one wood, giving rise to dazzling 'white carpets…

Mae'r siarc main yma’n cael ei enw o'r pigau o flaen ei asgell ddorsal. Gall ddefnyddio'r pigau yma i amddiffyn ei hun drwy gyrlio mewn bwa a tharo ysglyfaethwr.

Mae tylluanod brech yn dylluanod brown cyfarwydd yng nghoetiroedd, parciau a gerddi Prydain. Maent yn cael eu hadnabod am eu cân ‘tŵ-wit tŵ-hŵ’ sydd i’w chlywed yn ystod y nos.