Gellir gwełd y chwilod mawr, brown yma’n heidio o amgylch golau stryd yn y gwanwyn. Maen nhw’n byw o dan y ddaear fel larfa am flynyddoedd ac wedyn yn dod allan fel oedolion, mewn niferoedd mawr…

The knopper gall wasp produces knobbly red, turning to brown, growths, or 'galls', on the acorns of Pedunculate Oak. Inside the gall, the larvae of the wasp feed on the host tissues, but…

Traditionally a small finch of woodland and scrub, it appears that the lesser redpoll is now moving into our gardens. It has a streaky brown body, red forehead and black bib, and mostly feeds on…

The brown, oval flower heads of ribwort plantain balance on top of thin, wiry stems; the resulting seed heads provide food for birds in winter. Look for this 'weed' in lawns, fields and…

The tiny, brown wood mouse is one of our most common rodents and is very likely to be found in the garden. It is similar to the house mouse, but has larger ears and eyes relative to its size.

Great reedmace is familiar to many of us as the archetypal 'bulrush'. Look for its tall stems, sausage-like, brown flower heads and green, flat leaves at the water's edge in our…

The brown, oval, spiky seed heads of the teasel are a familiar sight in all kinds of habitats, from grassland to waste ground. They are visited by goldfinches and other birds, so make good garden…

The Sitka spruce was introduced into the UK from North America in the 19th century. It has been widely planted as a forestry tree; look for classic needle-like leaves and pale brown, domed cones…

The water vole is under serious threat from habitat loss and predation by the American mink. Found along our waterways, it is similar-looking to the brown rat, but with a blunt nose, small ears…

It's easy to see where the compass jellyfish got its name – its brown markings look just like a compass! They may look beautiful – but they give a nasty sting so keep your distance.

The giant house spider is one of our fastest invertebrates, running up to half a metre per second. This large, brown spider spins sheet-like cobwebs and pops up in the dark corners of houses,…

A common spider of heathland and grassland, the Nursery web spider has brown and black stripes running the length of its body. It is an active hunter, only using its silk to create a protective…