Belonging to the family Erythraeidae (Erythraeid mites), I often come across these arachnids scurrying about on retaining walls in my front and back gardens. These are fairly large red mites growing up to 2 mm long, and where their eyes are set back on elongate bodies. It is possibly a species called Balaustium murorum (Hermann, 1804), which has a preference for hard substrates like rock, stone, brick and concrete.
Seen all year round in various habitats including urban areas on walls and paving, they predate on other small invertebrates including springtails and other mites. They also feed on plants where they suck sap with their specialised piercing mouth parts, and can become a pest. Pollen is also a preferred food, and sometimes they can be found feeding in flowers. They are common and widespread throughout Britain.
All photos © Peter Hillman. Taken June 2019 & June 2021.