Additional interest lies in the flora that can tolerate high concentrations of lead in the soil such as spring sandwort (Minuartia verna) and the moss Ditrichum plumbicola.

Fifteen species of dragonfly have been recorded; as well as supporting the only population of downy emerald in the Mendips, the site hosts the notable four-spotted chaser (Libellula quadrimaculata) and ruddy darter (Sympetrum sanguineum).

Breeding birds include moorhen (Gallinula chloropus), coot (Fulica atra), mallard (Anas platyrhynchos), reed bunting (Emberiza schoeniclus) and sedge warbler (Acrocephalus schoenobaenus).

St Cuthbert's Swallet was formed by the erosive action of water flowing beneath the water-table at considerable depth (so called "phreatic development").

St Cuthbert's Swallet is a classic example of a deep phreatic cave system, containing inclined bedding plane mazes at many levels, fault-guided rifts and some significant chambers.