Scrub is a very important woodland habitat. While strenuous conservation effort is often needed to prevent species rich grasslands from disappearing under invading willow and blackthorn, this is more an indication of the rarity of the grassland, than a judgement on the conservation value of scrub. The different types and forms of scrubland in RCT represent an important habitat resource. On the valleyside ffridd, open stands of hawthorn and gorse, with intervening glades of rabbit grazed grassland, represent excellent invertebrate, reptile and nesting bird habitat.  Stands of willow scrub represent fantastic invertebrate habitat, in spring rich in nectar and in the summer home to countless, munching moth and sawfly larvae. Invading blackthorn scrub can be a management problem, but it represents the potential habitat of the rare brown hairstreak butterfly, which may still be discovered somewhere in RCT.